Updated 2.0.1 changelog
Bump the version number to 2.0.1
configure: fix qmake usage

./configure: QMAKE: not found
Fix #43: WARNING: Unescaped backslashes are deprecated

Just don't support custom installation location for
the provided .prf on Qt4/Win. Better than having loads
of such warnings...
Merge branch '2.0'

Conflicts:
	Doxyfile
	include/ircglobal.h
	version.pri