interface: Only generate double click event if mouse did not move more than a small amount

Fixes #77
Change automake rule for generating version_vcs.h to run only when in a Git repo.

This allows the version_vcs.h to be distributed in source packages and not be overwritten during compilation.
configure.ac: Add dist-xz and foreign option, and remove AUTHORS, ChangeLog and NEWS.
Bump to 0.1-rc2
Merge fixes from v0.1_rc2