stack: order the adjective of changeset
The new order give more interesting result:
* base current
* base unstable
* current unstable
It seems more harmonious this way. Base seems the most core and immutable
adjective describing the element. Then current is a volatile but important one.
Finally, unstable is less information than current, so it goes last.
#require test-repo pyflakes
Copied from Mercurial core (60ee2593a270)
$ cd "`dirname "$TESTDIR"`"
run pyflakes on all tracked files ending in .py or without a file ending
(skipping binary file random-seed)
$ hg locate 'set:(**.py or grep("^#!.*python")) - removed()' 2>/dev/null \
> | xargs pyflakes 2>/dev/null