purge old doc/plugins directory
purge olde PluginInstallerDialog context help

there will be a new QgsPluginManager help file
delete unused resource files

if I understand jef correctly, these files are all not used anymore (plz correct
me if I'm wrong).
The build and scripts incorporate the en_US resource files in the corresponding
i18n/qgis_**.ts files (by creating cpp from it).
Fix #4189
Partial fix #7708
Slovak translation update.
qgsexpression: lazy initialization of geometry calculator
raise Qt dependency to 4.5
- fix runtime gui warnings
- remove xpms
- also use qgis-icon-60x60.png as window icon on linux
labeling: fix missing fonts warning
debugging improvements
remove qgis.xpm from images.qrc (followup 8b5f22eef)
Fix some icon path warnings
use gdb only for crash reports (followup e4fed741)
add install of missing API headers
fix a3c1326
Fix #8366
[pyqgis-console] remove unused code
Merge pull request #773 from slarosa/fix_8366

Fix #8366
Switch from deprecated sip*Instance* calls to sip*Type* calls
Min SIP version 4.8