Port sidebar delegate to KColorScheme.

Certain KDE color schemes have Window Background and View Text
not contrasting, which causes invisible icon labels when using
QPalette::Text on QPalette::Base. An example is the default
color scheme in openSUSE 12.3.

Thanks to Will Stephenson for noticing.
CCMAIL:wstephenson@kde.org

It turns out that the Places sidebar in Dolphin suffers from
the same bug, so a similar change should be done there. Frank?
CCMAIL:frank78ac@googlemail.com
Cope with global color scheme changes in the page number entry.

CCMAIL:wstephenson@kde.org
Get rid of window background-colored bars between thumbnail containers.

This seems to be what the original code wanted to achieve, but failed
due to a convoluted approach of setting the color of the current back-
ground role to a default palette's Base color ... instead we just leave
the palette untouched and set the correct background role now. Visual
noise be gone, yay.

CCMAIL:wstephenson@kde.org
Move the page numbers a little higher.

Make sure there's no ambiguity that the page number refers to
the preceding thumbnail. This is a bigger deal because the fix
in b0f64d2 took away a visual divider.
Remove unused member, thanks to Albert for noticing the slip-up.
Txt backend

BUGS: 261930
REVIEW: 109009
FIXED-IN: 4.11.0
Fixlets to the txt backend
Move KColorScheme instanciation out of the paint path.

REVIEW:108958
use TryExec to not appear when not installed

when okular active is not installed, it should not appear in the open with menu, so add TryExec to see if the executable exists
this is used instead of conditional install to make easier for distributions to package the desktop and active versions separately

BUG:314981
REVIEW:109047
SVN_SILENT made messages (.desktop file)
SVN_SILENT made messages (.desktop file)
Expose the thin line support of poppler 0.24

Based on a patch by Thomas Freitag - Thomas.Freitag@alfa.de
Fix cmake condition
And now add the files i forgot

woops :D
poppler: fix typo
SVN_SILENT made messages (.desktop file)
poppler: i18n: extract messages also from .ui and .kcfg files
Merge remote-tracking branch 'okular/master' into font-selector-for-plain-text-formats
Merge remote-tracking branch 'okular/master' into font-selector-for-plain-text-formats