This puts the wxWidgets3.0 and libpng generated library files into the
deps folder, and puts the other builds files in a subdirectory from
where the project files are located. This is consistent with all the
other 3rdparty projects.
The output libraries for Devel builds are also suffixed with -dev
instead of -dbg now.
This configure the VS2013 files so that the now external libpng and
libjpeg libraries are used, and to place some of the common stuff into a
property sheet.
For deleted files, I've chosen to exclude from build instead of removing
them from the project file. It's less work to re-add them if they're
required at a later stage.
Jonathan Li