Enable mouse tracking in wxQT, thanks @seandepagnier

This is needed so qt mouse events are triggered without a button pressed.
Note that I modified this to prevent a crash if m_qtWindow was null (reproducible with controls sample and the original patch from Sean)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77925 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Fix case where widgets may get hidden by qt, thanks @seandpagnier

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77926 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Block qt signals when manually setting value to avoid emitting an event in wxQT, thanks @seandpagnier

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77927 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Improve slider implementation in wxQT, thanks @seandpagnier

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77928 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Improve wx->qt filter mapping logic in wxQT, thanks @seandpagnier

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77929 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Add inverted flag support to slider in wxQT, thanks @seandpagnier

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77930 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Correct window transparency calculation in wxQT, thanks @seandpagnier

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77931 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Copy pixmap to match others ctors in wxQT, thanks @seandpagnier

This should fix a double free crash

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77932 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Implement readonly dcscreen for wxQT, thanks @seandpagnier

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77933 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Remove redundant __WXQT__ define, thanks @seandpagnier

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77934 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Improve specific listctrl wxQT, thanks @seandpagnier

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77935 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Fix listctrl base window pointer in wxQT, thanks @seandpagnier

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77936 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Allow setting font and brush in DC when the qt painter is not active in wxQT, thanks @seandpagnier

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77937 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Merge pull request #3 from wxWidgets/master

Sync