Add spatial navigation option
Merge pull request #859 from pejakm/spatn

Add spatial navigation option
[Windows] Updated Windows installer.
Updated CHANGELOG and README.md for 1.4.2 release.
[Toolbar] Use spacing and margins according to Qt style.

Toolbar looks better now with Oxygen theme.
[Linux theme] Small tweaks in locationbar icons.

Using theme icon for GoIcon. Removed explicitly setting padding.
[ToolBar] Use size of icons according to Qt style.
[WebSearchBar] Use search icon from theme.
[Themes] Set navigationbar layout margin and spacing from style sheet.
[Windows Installer] Added Serbian language into installer.
[Code] Improved cppcheck script and fixed all warnings.
[AdBlock] Added ABPindo (Indonesian) into known subscriptions.