Remove the concept of observer/view id

Just use the pointer as id :-)

This is BIC and SIC, increase the soversion now to makes sure we don't forget in the future

Patch based in an earlier patch by Bogdan Cristea <cristeab@gmail.com>
REVIEW: 109115
SVN_SILENT made messages (.desktop file)
Renamed dummy extraction file rc_okular_poppler.cpp to usual rc.cpp.

When special dummy file name is used, it needs to be listed in
the l10n-kde4/scripts/repack-pot.pl script. So when the special
name is not necessary, better use the usual one.
rename rc_okular_ghostview.cpp to usual rc.cpp
Merge remote-tracking branch 'okular/master' into font-selector-for-plain-text-formats