perf: use standard arguments for perfrevlog
We have a convention of using -c|-m|FILE elsewhere for reading from
revlogs. Use it for `hg perfrevlog`.
While I was here, I also added a docstring to document what this
command does, as "perfrevlog" is ambiguous.
test-extension: do not depend on demandimport (
issue5012)
When demandimport is disabled, the test will fail because extroot/foo.py uses
import outside PYTHONPATH. This is bad since we have a PyPy migration plan and
it does not support demandimport. Fix by setting PYTHONPATH.