split my long stderr message, displaying details only if called by raw_input

Rather than overwhelming users with verbiage, I will hide most of my explanation unless it's asked for. My message is still not particularly brief, but it's no longer insanely long.
add a <title> to UMC listing pages

As I read it, basename() should not be required for path, and I've tested this locally.
make image_reference match jpeg as well as jpg extension
fix <title> to only display branch directory

OK, so it turns out basename() was required after all!
push_back Windows-style "Copy of" backup files
revert last commit (push_back "Copy of") per IRC discussion with shadowmaster
Merge pull request #1 from wesnoth/master

Test