This is the convention suggested in the Sphinx documentation and is
already used in several other places in the CMake documentation.
Update a few places where we were using other characters.
Add an introduction about the use of different package types, and the
ability to use Qt 4 and 5 versions together in a single buildsystem.
Add a section about automatic linking of the qtmain.lib library and
how to disable it.
Brad King
Stephen Kelly