graft: moved abortgraft and readgraft to cmdutil
This patch moves `abortgraft` and `readgraft` to
`cmdutil`. Various callers are updated accordingly.
This is done because these serve as ulitlity functions
for command `graft` and so that new functions regarding
graft can be built from them.
Differential Revision: https://phab.mercurial-scm.org/D6608
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.