Don't ask for write access in rogg_stats.

Also wrap a line in rogg_pagedump.c from when the same
change was made there.
Add a script for twiddling Kate parameters.

I needed to twiddle the canvas size in a kate stream, and I thought
rogg would be perfect for this kind of thing, and it turned out to be.
Add a .gitignore for cleaner status output.
Use git revision in dist tarball name, if possible.

We still need a static version so builds from release
tarballs work, or checkouts where git itself is unavailable.
Don't remove distdir twice.
Add 'make distcheck' target.