Removed unused icons

While looking for the icons so luisa could create svg
versions of them, I found out a few things that are not
used anymore.

Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

subsurface.qrc

@@ -22,15 +22,6 @@
         <file alias="scale">icons/scale.png</file>
         <file alias="ruler">icons/ruler.png</file>
         <file alias="poster">icons/poster.png</file>
-        <file alias="arrow_up">icons/planner/arrow_up.png</file>
-        <file alias="arrow_down">icons/planner/arrow_down.png</file>
-        <file alias="icon_time">icons/planner/icon_time.png</file>
-        <file alias="icon_depth">icons/planner/icon_depth.png</file>
-        <file alias="round_base">icons/planner/round_base.png</file>
-        <file alias="right_wing">icons/planner/right_wing.png</file>
-        <file alias="left_wing">icons/planner/left_wing.png</file>
-        <file alias="plan_minus">icons/planner/minus.png</file>
-        <file alias="plan_plus">icons/planner/plus.png</file>
         <file>xslt/commonTemplates.xsl</file>
         <file>xslt/csv2xml.xslt</file>
         <file>xslt/divelogs-export.xslt</file>