evolve: add a utility fn to check validity of opts passed to `hg evolve`

evolve: don't use graftstate for continuing `hg evolve` Before this patch, if user runs `hg evolve`, we read the evolve state, write a graftstate from that information and run graft command. This patch replaces that logic with new logic which does not depends on the graft state. The new logic is very filtered part of logic from graft command. We did not require a lot of opts checking and filtering revs logic from the graft command as our use case is fixed. This is the start of series/work which will make `hg evolve` better and have a good statefile for itself.

topics: add a new templatekeyword `topic` This patch adds a new templatekeyword topic which can be used to list the topic of the changeset when using commands which supports templating.

packaging: update MANIFEST.in to include new tutorial files I forget to update the MANIFEST.in file when important the new tutorial files. This commit fix that.

test-compat: merge mercurial-4.2 into mercurial-4.1

test-compat: merge mercurial-4.3 into mercurial-4.2

test-compat: merge stable into mercurial-4.3

test: add a test to reproduce issue 5720

test: add missing cycle test Also fix precursors to break on obs markers cycles.

Small typos fixing in the topic tutorial