"Professional CMake" book suggest the following:
"Targets should build successfully with or without compiler support for precompiled headers. It
should be considered an optimization, not a requirement. In particular, do not explicitly include a
precompile header (e.g. stdafx.h) in the source code, let CMake force-include an automatically
generated precompile header on the compiler command line instead. This is more portable across
the major compilers and is likely to be easier to maintain. It will also avoid warnings being
generated from certain code checking tools like iwyu (include what you use)."
Therefore, removed the "#include <PreCompiled.h>" from sources, also
there is no need for the "#ifdef _PreComp_" anymore
A new document object App::TextDocument. It has a property Text which
holds the text of the document as a string. This commit also contains a
full size editor based on QPlainTextEdit. It can only be used by the
TextDocument and has a read only mode invoked for read only documents
(ReadOnly property set to true). The editor is invoked by a double
click on the TextDocument.
