tests: rename the test file to add 'orphan' in the name test-evolve-stop.t contains test for `hg evolve --stop` for orphan resolution only. We also need to test the flag while resolving divergence. It will be good if we have a test file for each type of instability.

tests: test that `hg obslog wdir()` aborts with a useful message

obshistory: make obslog work when a commit doesn't have any description This logic is taken from logcmdutil.changesetprinter class. It checks that commit description is not empty before extracting the first line (before this patch it would try to index an empty list). Stripping description also makes obslog behave more like regular log when there are trailing/leading whitespaces.

obshistory: use a more appropriate type for obslog entries cand is actually a regular changeset and not 'M' (graphmod.MISSINGPARENT). And 'M' is only used for graph edges, but cand is drawn as a graph node. Visually there's no effect, but the code makes more sense this way.

packaging: mark as development version This help avoiding confusion when installing from source.

branching: merge with latest release

packaking: mark as development version This avoid confusion when installing from source.

test-compat: merge mercurial-4.4 into mercurial-4.3

test-compat: merge mercurial-4.5 into mercurial-4.4

test-compat: merge stable into mercurial-4.5