Create our first Doxyfile and doxygen script.
Preeeeety colours
Add experimental support to push to GitHub pages for documentation.
Move the git configuration stuff to the instance config, and out of our own script.
Only deal with our main repository when pushing.
Move the documentation publishing code to the build config so that people cannot PR and clobber our documentation...
Move variable definitions.
Remove trailing newline.
Be explicit about paths.
Use 7-zip if it is on the command line.
We will cache the doxygen zip file.
Convert Doxygen warning messages to AppVeyor warnings.
Fix AppVeyor API call.
Support multiple messages in one block of output.
Also write the error messages to the message log.
Merge remote-tracking branch 'remotes/origin/implement-doxygen'

Conflicts:
	.gitignore