add/fix basic tests for wxqt

[reingart]

Testing the Controls' sample, runtime checks and assertions would be added to assure that fixes are working correctly.
Also, I'll like to review the code to avoid memory leaks / qt signal disconnection issues on destruction (due new syntax), and polish any eventual codding issue (including refactor to qt thin and simplified helpers, see 51da1ea and 7aa4fad).
Finnally, I'll focus on add/update comments and documentation

[reingart]

Controls sample is working and functional, removed pending issues and improved control support (IMHO wxQT could be used to develop simple applications now).

Summary:

• Made qt helpers internal and thin (almost no trivial methods)
• Fixed calendar control
• Fixed check list control
• Completed minimal implementation of text control
• Refactorized combobox and buttons
• Fixed notebook events (better implementation)
• Fixed SIGSEGV on paint event
• Template helper moved to private header
• Revised prior commits (ie new wxGA_TEXT style)
• Added and fixed slider ticks
• Minor fixes and improvements

After some investigation, qt signal disconnection should not pose any problem as wxQT is not using lambdas (and signals are automatically disconected when object are destroyed, and it is not using cross signal/slot object connections: qt helpers are thin and connect they own signals inside to their own methods).
Some asserts and checks where introduced to controls sample, but it is not wise to keep adding stuff there, it would be better to fix tests.

New issues open for future milestones (almost all are previous topics not introduced in this gsoc):

• Refactor to use RAII: Refactor saving/restoring brush #17 (VADZ)
• Clean up (remove Qt from wxBase and warning): wxBase shouldn't depend on Qt libraries #18 Many warnings during build #19 (VADZ)
• Memory leaks / problems reported by Valgrind: valgrind: memory leak in wxWindow ctor Init() macro #21 valgrind: uninitialized m_rasterColourOp in wxQtDCImpl::ApplyRasterColourOp() #22 valgrind: memory leak at wxBitmapRefData ctor #23 valgrind: memory leak at wxFrameBase::OnCreateStatusBar #24 valgrind: memory leak when creating new wxMenu #25
• Revise naming conventions: wxQT naming convention inconcistencies #26
• Revise internal headers: Move internal utility functions headers to private #27
• Revise documentation: Documentation and Coding Style inconcistencies #28