add StartupWMClass= to .desktop files (bnc#777070)

The actual purpose is to help Plasma taskbar associate taskbar items
with .desktop files for the purpose of creating launchers. LibreOffice's
WM_CLASS handling is rather broken, but the class part of it usually
ends up being 'libreoffice-<component>', which however doesn't match
names of .desktop files or executables. I fear renaming .desktop files
would cause too much breakages in various places that expect the current
names, so adding StartupWMClass will help Plasma match them.

Change-Id: Ia946307b429d9a7c00408b2b508726fdc88908ac

sysui/desktop/menus/base.desktop

@@ -31,6 +31,7 @@ X-GIO-NoFuse=true
 Keywords=Data;SQL;
 InitialPreference=5
 X-Ayatana-Desktop-Shortcuts=X-New
+StartupWMClass=libreoffice-base
 [X-New Shortcut Group]
 UnityQuicklist=New Database
 Exec=libreoffice --base %%FILE%%

sysui/desktop/menus/calc.desktop

@@ -31,6 +31,7 @@ X-GIO-NoFuse=true
 Keywords=Accounting;Stats;OpenDocument Spreadsheet;Chart;Microsoft Excel;Microsoft Works;OpenOffice Calc;ods;xls;xlsx;
 InitialPreference=5
 X-Ayatana-Desktop-Shortcuts=X-New
+StartupWMClass=libreoffice-calc
 [X-New Shortcut Group]
 UnityQuicklist=New Spreadsheet
 Exec=libreoffice --calc %%FILE%%

sysui/desktop/menus/draw.desktop

@@ -31,6 +31,7 @@ X-GIO-NoFuse=true
 Keywords=Vector;Schema;Diagram;Layout;OpenDocument Graphics;Microsoft Publisher;Corel Draw;cdr;odg;svg;
 InitialPreference=5
 X-Ayatana-Desktop-Shortcuts=X-New
+StartupWMClass=libreoffice-draw
 [X-New Shortcut Group]
 UnityQuicklist=New Drawing
 Exec=libreoffice --draw %%FILE%%

sysui/desktop/menus/impress.desktop

@@ -31,6 +31,7 @@ X-GIO-NoFuse=true
 Keywords=Slideshow;Slides;OpenDocument Presentation;Microsoft PowerPoint;Microsoft Works;OpenOffice Impress;odp;ppt;pptx;
 InitialPreference=5
 X-Ayatana-Desktop-Shortcuts=X-New
+StartupWMClass=libreoffice-impress
 [X-New Shortcut Group]
 UnityQuicklist=New Presentation
 Exec=libreoffice --impress %%FILE%%

sysui/desktop/menus/math.desktop

@@ -32,6 +32,7 @@ X-GIO-NoFuse=true
 Keywords=Equation;OpenDocument Formula;Formula;odf;
 InitialPreference=5
 X-Ayatana-Desktop-Shortcuts=X-New
+StartupWMClass=libreoffice-math
 [X-New Shortcut Group]
 UnityQuicklist=New Formula
 Exec=libreoffice --math %%FILE%%

sysui/desktop/menus/startcenter.desktop

@@ -29,3 +29,4 @@ GenericName=Office
 Comment=The office productivity suite compatible to the open and standardized ODF document format. Supported by The Document Foundation.
 StartupNotify=true
 X-GIO-NoFuse=true
+StartupWMClass=libreoffice-startcenter

sysui/desktop/menus/writer.desktop

@@ -31,6 +31,7 @@ X-GIO-NoFuse=true
 Keywords=Text;Letter;Fax;Document;OpenDocument Text;Microsoft Word;Microsoft Works;Lotus WordPro;OpenOffice Writer;CV;odt;doc;docx;rtf;
 InitialPreference=5
 X-Ayatana-Desktop-Shortcuts=X-New
+StartupWMClass=libreoffice-writer
 [X-New Shortcut Group]
 UnityQuicklist=New Document
 Exec=libreoffice --writer %%FILE%%