PyQt4 frontend, debian package

New features:
Simple frontends selection system with predefined frontends and option in config for changing current frontend.
Cache directory (used for favicons) detection.
New config options: current frontend, window width and height, favicon downloading feature (see below).
Debian specs for building DEB packages.
Fallback icons (useful in Windows OS).

PyQt4 frontend.
Cross-platform, tested with GNU/Linux and Windows OS.
Compatible with Py2Exe.
Simplified common UI logic for opening/creating a database.
Tree view for group of items (only 1 level of groups is supported)
Downloading favicons from websites defined in URL record (option is disabled by default, because its related to privace, also feature can be unstable)
Settings window has 2 new options: frontend, favicons

Not yet implemented:
About window, merging feature.