Fixed Issue #1
Allow user to get visible lines, start/end offset
Implemented Big File Support
Minor fixes and improvements everywhere (painting, selection, undo/redo,
text handling, shortcuts)
Removed useless classes QHexEditDataManager
Implemented baseAddress() and setBaseAddress() methods (Fixes #2)
QHexEditData: Implemented save() and saveTo() methods
QHexExitData: Make constructor private
Updated README.md
Merge remote-tracking branch 'upstream/master' into test-merge

Conflicts:
	qhexeditprivate.cpp
	undocommands.cpp
	undocommands.h