hghave: add test for whether fsmonitor is enabled This uses the HGFSMONITOR_TESTS environment variable that fsmonitor-run-tests.py adds.

tests: add a wrapper to run fsmonitor tests This script does a bunch of non-trivial configuration work: in particular, it sets up an isolated instance of Watchman which isn't affected by global state and can be torn down on completion. This script also sets the HGFSMONITOR_TESTS environment variable, which hghave will use in the next patch to allow gating on whether fsmonitor is enabled. With fsmonitor enabled, there appear to be a number of failures in the test suite. It's not yet clear to me why they're happening, but if someone would like to jump in and fix some of them I hope this will be helpful for that.

setdiscovery: improves logged message The 'srvheads' list contains all server heads including the common ones. We adjust 'ui.log' message to provide more useful information about server heads locally unknown. The performance impact of turning the list to set is negligible (about 1e-4s) compared to the rest of the discovery cost, so I'm taking the easy path.

tests: handle variation between pure and normal output in annotate --skip I'm pretty sure that both results are valid, depending on how you slice the edits.

bisect: improve option validation message

context: inline makememctx (API) I have always thought it weird that we have a helper method instead of just using __init__. So, I ripped it out.

context: add convenience method for returning a memfilectx from a patch This is mostly a copy of what makememctx does but refactored to make it behave more like our other convenience methods.