revset: changed lazyset __add__ implementation to work lazily
Performance Benchmarking:
$ time hg log -qr "first(author(mpm) or branch(default))"
0:
9117c6561b0b
real 0m3.875s
user 0m3.818s
sys 0m0.051s
$ time ./hg log -qr "first(author(mpm) or branch(default))"
0:
9117c6561b0b
real 0m0.213s
user 0m0.174s
sys 0m0.038s
obsstore: add a __len__ method
We can already use "for mark in store:" it make sense to allow
"len(store)" too.
obsstore: `create` method return True if a marker is actually added
The obsstore method now have a return value. This informs caller about the
actual creation of a new markers. No new markers are created if it would have
been a duplicate.
test-help.t: add test for 'hg help extensions'
This demonstrates the defect that deprecated extensions show up in the
output. A followup patch will fix this defect.