User manual: updates to undo description

And some trailing space removal.

The text on editing dives hopefully is more accurate and easier to understand.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

Documentation/user-manual.txt

@@ -229,24 +229,25 @@ of each dive. These panels are respectively marked [red]#A#, [red]#B# and
 in the figure below. Each of these tabs will now be explained for data entry.
 
 image::images/AddDive1_f22.jpg["FIGURE: Add dive",align="center"]
-When you edit a field in the Notes or Equipment panels, _Subsurface_ enters *Editing Mode*,
+
-indicated by the message in the blue box at the top of the *Notes* panel (see the image below). This message is
+Most actions when editing a new dive can be individually undone, as described in the
-displayed in all the panels under Notes and Equipment when in *Editing Mode*.
+section on <<S_undo,undoing edits>>, but changes
+in the Equipment panel are not yet included in that in-depth undo implementations, and therefore
+_Subsurface_ enters *Editing Mode* when changes are made in this panel. This is
+indicated by the message in the blue box at the top of the panels (see the image below).
 
 image::images/BlueEditBar_f22.jpg["Blue edit bar",align="center"]
 
-If this hand-entered dive was away from the sea you may wish to edit the xref:S_altitude[*altitude setting in the
+The _Apply changes_ button should be selected after all the equipment for a dive has been entered.
+
+If this hand-entered dive was not in the sea but in a body of water above sea level you may wish to edit the xref:S_altitude[*altitude setting in the
 Information panel*] because dives at altitude need special calculations.
 
-The _Apply changes_ button should only be selected after all the parts of a dive have been entered.
+All edits to a new dive, including changes to the equipment after
-When entering dives by hand, the _Info_, _Equipment_ and _Profile_ tabs should be completed
+selecting the _Apply changes_ button, are
-before applying the information. By selecting the _Apply changes_ button, a local copy of the information
+saved in memory but NOT written to storage.
-for this specific dive is saved in memory but NOT written to disk.
+If you don't manually save them before closing Subsurface, the program will
-The _Apply changes_ button should ONLY be selected after all parts
+ask again, this time whether the complete dive log should be saved to storage or not.
-of a dive have been entered. When closing Subsurface, the program will
-ask again, this time whether the complete dive log should be saved on disk or not.
-
-Click here to find out xref:S_undo[*How to UNDO changes while typing information*]
 
 [[S_CreateProfile]]
 ==== Creating a Dive Profile
@@ -703,16 +704,17 @@ edited directly by clicking on each of them in the text box and by over-typing t
 information displayed.
 
 [[S_undo]]
-*How to UNDO information that has been typed.* While editing a dive log one frequently
+*How to UNDO information that has been typed.* While editing a dive log you frequently
-overtypes existing information. Sometimes this is unintended. Let's say, for the moment,
+replace or modify existing information. Sometimes this is unintended. Let's say, for the moment,
-the time of your dive computer was set wrongly and the dive time in the
+the time of your dive computer was set incorrectly and the dive time in the
 *Notes* tab is therefore incorrect. You wish to correct the time indicated in the *Notes* tab
 to reflect the true dive time. The example in the images below reflect a small part
 of the *Notes* tab where the dive time was changed from
 8:44 (image a) to 7:44 (image b). Now, for some reason, you wish to return
 to the initial time (08:44). Click on the _Edit_ heading in the main menu and
 an option appears to undo the change in time (image c). Select this undo option
-and the time is again shown as 8:44. Having undone the change, a new option appears under
+and the time is again shown as 8:44. This can also be achieved by typing Ctrl-Z (or CMD-Z on a Mac).
+Having undone the change, a new option appears under
 the _Edit_ heading: Redo the change (image d). If this option is selected, the change in
 time is redone. The undo facility applies to the majority of information typed into the text
 areas of _Subsurface_ and facilitates easy and accurate data entry. Multiple changes
@@ -1491,7 +1493,7 @@ the dive named at the top of the panel and returns you to the dive sites managem
 
 At the top right of the dive sites management table is a round button with a "+". Clicking that button inserts a
 new site entitled "New dive site" into the list (image below). The new site can also be deleted (maybe after erroneously
-clicking the + icon or you realised the dive site already exists) by selecting _Edit -> Undo_ from the main menu or by typing Cntrl-Z while the dive sites management table has focus. Edit this new site by selecting its edit icon and provide a name,
+clicking the + icon or you realised the dive site already exists) by selecting _Edit -> Undo_ from the main menu or by typing Ctrl-Z (or CMD-Z on a Mac) while the dive sites management table has focus. Edit this new site by selecting its edit icon and provide a name,
 coordinates and, if preferred, a description. Clicking
 the "Done" button in the edit panel returns you to the dive sites management panel.