svn: increase possibility to specify compatability to 1.9. - now possible to spec pre-1.9-compat.

vcsserver: add debug information to some of the errors that might happen.

ini: updated production ini with latest changes

mercurial: expose remote method to get commit phase

extensions: added hg-evolve package

core: finished removal of pyro4. backend is no longer available to be used. We rely purely on http implementation.

release: merge back stable branch into default

Added tag v4.7.2 for changeset f9b09787da98

release: Finish preparation for 4.7.2

release: updated pip2nix output for 4.7.2