Add wxGA_TEXT style for text percent in wxQT gauge
Honor slider tick position style flags in wxQT
Add wxQtLineEdit helper for single line TextCtrl

Events similar to wxGTK (wxEVT_TEXT and wxEVT_TEXT_ENTER, checking wxTE_PROCESS_ENTER style flag)
Implement proper set value method for wxTextCtrl

 * Send events depending on flags (blocking qt signals)
 * Replace all the text without sending two events (removal and insert like wxGTK)

Note that this add stub methods in wxTextEntry just for consistency.
This should be revisited evaluating if wxTextEntry implementations is required at all (seems qt has different text entry controls methods so there could be nothing in common)
Add wxQtTextEdit helper for multiline text control

Note that only wxEVT_TEXT is implemented by now as qt lacks returnPressed signal in QTextEdit.
Also, the signal textChanged has no parameter for QTextEdit, so text entries are not uniform in Qt regarding events notifications too.
This also raised an issue with GetValue() called inside the event when setting the initial text (that don't have to be sent according the docs), so see the next commit
Add wxQtTextEdit helper for multiline text control

Note that only wxEVT_TEXT is implemented by now as qt lacks returnPressed signal in QTextEdit.
Also, the signal textChanged has no parameter for QTextEdit, so text entries are not uniform in Qt regarding events notifications too.
This also raised a SIGSEGV, issue with GetValue() called inside the event when setting the initial text (that was changed as it don't have to be sent according the docs), so please see the next commit
Move setting initial text before CreateControl

Note that CreateBase (in QtCreateControl) was not being called before setting the initial text value (ChangeValue), hence basic methods like HasFlag or IsMultiline weren't working at that point (and this caused a SIGSEGV in wxTextCtrl as it relies on flags to distinguish between m_qtLineEdit and m_qtTextEdit)
In wxGTK CreateBase is called explicitly before creating the gtk control (for example, in wxTextCtrl::Create)
Add test text event methods to controls sample