upgrade: register all format variants in a list
Now that all known format variants exists outside of the function, we can gather
them in a lists. This build a single entry point other code can use (current
target: extensions).
The repository upgrade code is updated to simply use entries from this list.
As a side effect this will also allow extensions to register their own format
variants, to do this "properly" we should introduce a "registrar" for this
category of object. However I prefer to keep this series simple, and that will
be adventure for future time.
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.