Add info about SmartTrak import

Signed-off-by: Salvador Cuñat <salvador.cunat@gmail.com>

Documentation/user-manual.txt

@@ -1238,6 +1238,69 @@ size of the _CSV_ file might cause problems. Importing 100 dives at a time
 the limits of the parser used. When encountering problems with _CSV_ imports, first try with
 a smaller file to make sure everything works.
 
+[[S_SmartTrakImport]]
+==== Importing SmartTrak divelogs
+
+SmartTrak is a Windows based propietary software by Uwatec (today Scubapro).
+It works through Access databases, which makes it difficult to integrate the
+importer in _Subsurface_ core application, and stores the full raw data from
+the DC along with a plethora of other data manually added by the user, ranging
+from dive points to buddies data or DAN survey info.
+
+A little stand alone tool has been developed to import the .slg files
+generated by SmartTrak to Subsurface's .xml format. It can be built together
+with _Subsurface_ for linux systems. Two dependencies need to be installed in
+your system before building: libglib2.0 and libmdb2.
+
+Assuming installed those dependencies and _Subsurface_ source tree placed in a
+directory like ~/src/subsurface, then:
+
+*BUILDING*
+
+- Move to the source tree directory.
+- Run  " $ ccmake build " and set SMARTTRAK_IMPORT option to *on* (off by
+  default).
+- Generate with [c] and save and exit with [g].
+- Build as you prefer, using build.sh script (recomended) or moving to build
+  directory and running make.
+- After a successful build, there will be an executable in the build directory
+  named smtk2ssrf, copy or move it to a directory in your $PATH, e.g. ~/bin
+
+*RUNNING*
+
+smtk2ssrf accepts 0, 2 or more parameters. If it's launched without
+parameters and you are on a graphical environment a simple window will be
+displayed letting you choose the file(s) to import and a file to store the
+subsurface formatted data.
+
+[icon="images/icons/warning2.png"]
+[WARNING]
+Previous data in the output file will be
+erased, so *DO NOT* use your regular subsurface divelog file as output. It's
+advisable to set a brand new file to do the import.
+
+If launched from command line with 2 or more parameters like:
+
+	$ smrtk2ssrfc /input/file_1.slg /input/file_2.slg /output/file.xml
+
+Files file_1.slg and file_2.slg in input directory will be imported and stored
+in file.xml in output directory.
+
+Check warning and error messages in console or graphical window, some may be
+interesting, as support for Galileo and family DCs is still a work in
+progress.
+
+*MERGING*
+
+Open the brand new imported file in _Subsurface_ and check the dives and data.
+If everything is fine, close the .xml file and open your regular divelog.
+Then from _Main menu_ select _Import -> Import log file_ and choose the
+imported .xml file.  The imported dives will show in the _Dive List_, time
+ordered, along with the previous dives.
+The new dives, although time ordered, will keep the numbering system from
+SmartTrak, so a renumbering action is needed. See xref:S_Renumber[Renumbering
+the dives] section in this manual for instructions about this topic.
+
 
 === Importing Dive coordinates from a mobile device with GPS.