[ComboTabBar] Fixed incorrectly changing current index when closing tabs in inactive tabbar.
[Downloads] Make sure to always add slash '/' between path and filename
[ComboTabBar] Fix flickering when (un)pinning tabs
[MinGW] Some fixes for MinGW building

Conflicts:
	src/lib/lib.pro
[LocationBar] Don't incorrectly show about to be loaded url when it was not accepted

It can happen for example when trying to change address on a page that
handles window.onbeforeunload event