update: add comments and test cases for updating across branches Add comment to merge.py:update() showing various cases of 'hg update': to a descendant, crossing named branches, and crossing branches within a named branch; with no option, -c or -C; with or without uncommitted changes; and with or without a specific revision. Add tests for all of these cases.

Basic install:

 $ make            # see install targets
 $ make install    # do a system-wide install
 $ hg debuginstall # sanity-check setup
 $ hg              # see help

See http://mercurial.selenic.com/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.