Prepare for being able to add find flags that are not in QTextDocument

src/plugins/bineditor/bineditorplugin.cpp

src/plugins/find/basetextfind.cpp

src/plugins/find/basetextfind.h

src/plugins/find/currentdocumentfind.cpp

src/plugins/find/currentdocumentfind.h

src/plugins/find/findplugin.cpp

src/plugins/find/findplugin.h

src/plugins/find/findtoolbar.cpp

src/plugins/find/findtoolbar.h

src/plugins/find/ifindfilter.h

src/plugins/find/ifindsupport.h

src/plugins/help/helpfindsupport.cpp

src/plugins/help/helpfindsupport.h

src/plugins/texteditor/basetexteditor.cpp

src/plugins/texteditor/basetexteditor.h

src/plugins/texteditor/basetexteditor_p.h