Improved .desktop and menu file

Thanks to Fryderyk Dziarmagowski for providing a patch for the .desktop
file of LMMS. It should be standard conform now. An icon is now
explicitely installed in /usr/share/pixmaps so the .desktop and menu
files can specify a generic icon name rather than an absolute file path
to a PNG file of LMMS' default theme.
(cherry picked from commit 4d3040297c)

data/CMakeLists.txt

@@ -6,6 +6,7 @@ ADD_SUBDIRECTORY(samples)
 ADD_SUBDIRECTORY(themes)
 
 IF(LMMS_BUILD_LINUX)
+INSTALL(FILES themes/default/icon.png DESTINATION ${DATA_DIR}/pixmaps RENAME lmms.png)
 INSTALL(FILES lmms DESTINATION ${DATA_DIR}/menu)
 INSTALL(FILES lmms.desktop DESTINATION ${DATA_DIR}/applications)
 INSTALL(FILES lmms.xml DESTINATION ${DATA_DIR}/mime/packages)

data/lmms

@@ -1,4 +1,4 @@
 ?package(lmms):needs="X11" section="Apps/Sound" \
   title="LMMS" hints="Audio" command="/usr/bin/lmms" \
   longtitle="Linux MultiMedia Studio" \
-  icon="/usr/share/lmms/themes/default/icon.png"
+  icon="/usr/share/pixmaps/lmms.png"

data/lmms.desktop

@@ -5,10 +5,9 @@ GenericName[ca]=Programari de producció musical
 GenericName[de]=Software zur Musik-Produktion
 Comment=easy music production for everyone!
 Comment[ca]=Producció fàcil de música per a tothom!
-Icon=/usr/share/lmms/themes/default/icon.png
-Exec=/usr/bin/lmms
+Icon=lmms
+Exec=lmms
 Terminal=false
 Type=Application
-Encoding=UTF-8
-Categories=Application;AudioVideo;Qt
-MimeType=application/x-lmms-project
+Categories=Qt;AudioVideo;Audio;Midi;
+MimeType=application/x-lmms-project;