Cleanup of autogenerated build scripts

Makefile.in is generated from Makefile.am, and shouldn't be in SCM (but
in a .tar.gz, where the source comes from)

There are other files that shouldn't be there either. Clean up.

Signed-off-by: Max Sikstrom <msikstrom@op5.com>
Update .gitignore, and readd COPYING

COPYING is needed by autoreconf, so we use that file instead.

Also update .gitignore to match this project

Signed-off-by: Max Sikstrom <msikstrom@op5.com>