add HGRCPATH env var, list of places to look for hgrc files. if set, override default hgrc search path. if empty, only .hg/hgrc of current repo read. for each element, if directory, all entries in directory with end in ".rc" are added to path. else, element is added to path. big thing about this change is that user "~/.hgrc" and system hgrc not longer breaks tests. run-tests makes HGRCPATH empty now.

#!/bin/sh

hg init
touch unknown

touch a
hg add a
hg ci -m "1" -d "1000000 0"

touch b
hg add b
hg ci -m "2" -d "1000000 0"

echo %% Should show unknown
hg status
hg revert -r 0
echo %% Should show unknown and b removed
hg status
echo %% Should show a and unknown
ls