rebase: change "result would have 3 parent" error message (BC)
The old error message "cannot use revision REV as base, result would have 3
parents" is confusing - why use REV as base? why add a new parent?.
This patch changes it to "cannot move parent", which seems better.
Differential Revision: https://phab.mercurial-scm.org/D342
Mercurial
=========
Mercurial is a fast, easy to use, distributed revision control tool
for software developers.
Basic install::
$ make # see install targets
$ make install # do a system-wide install
$ hg debuginstall # sanity-check setup
$ hg # see help
Running without installing::
$ make local # build for inplace usage
$ ./hg --version # should show the latest version
See https://mercurial-scm.org/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.