[Travis] Build only master and v1.6 branches
[ComboTabBar] Move right/left containers to ComboTabBar class

It is now possible to set corner widgets of all tabbar, not only
main tabbar.
[WebTab] Move more code into WebTab, instead of handling in TabWidget/TabBar

This also fixes showing tab icon after detaching tab
[DuckDuckGo] Use new icon for DuckDuckGo search engine
[TabBar] Fixed showing 2 AddTab buttons when tabs overflows
Fix compile issue with plugins on msvc.
Fix msvc compile issue in tabwidget.
Fix msvc compile issue in mainapplication use of undefined type
RegisterQAppAssociation
Fix msvc compile issue with datapaths
Fix msvc compile error m_usingTransparentBackground undeclared
identifier
Fix msvc compile issue m_navigationBar undeclared identifier
Merge pull request #1264 from K0r5hun/master

Fix some issues for msvc compile
[SearchEngines] Support for loading POST engines from LocationBar

Added new class LoadRequest, that holds network request with its
operation type and POST data.
[Windows] Fixed inserting QUnicodeControlCharacterMenu to contextmenu.
[WebHistoryWrapper] Removed unused WebHistoryWrapper class
[TabbedWebView] No need to override stop() method
[TabWidget] Fix showing empty tab title when adding new tab

Regression from recent commits
add es_ES language translated
Merge pull request #1266 from javierllorente/es_ES

add es_ES language translated
[SiteIcon] Support :pressed state for style sheets