obslog: more 4.1 code compatibility drop

template: drop some 4.1 compatibility code Simplify all the things.

checkheads: drop upstreamed code Mercurial 4.2 has all the code that used to live in the evolve extensions so we can drop it now.

obslog: cleanup patch handling after 4.1 compat drop We can remove some of your compatibility code.

packaging: further mark 4.1 support as dropped

branching: merge with stable

tests: extend the globing to the user name Silly me.

branching: close mercurial-4.1 test branch

evolve: kill `--obsolete` and `--old-obsolete` flags for graft Evolve extension used to add the couple of flags to `hg graft` command for reasons I don't know but they were deprecated. For the functionality of `hg graft --old-obsolete`, we have `hg grab` now which can do that. One more reason to kill this is that we have logic to parse the graftstate, whereas in core, we are going to change how state files are read and write. Tweaked the tests a bit to use `hg grab` instead of these flags to make rest of the test output consistent. Replaced an entry of `hg graft -O` in doc by `hg grab`.

compat: drop support for Mercurial 4.1 This version is over 1 year old and we are dropping support for it.