run merge program in repo root.
before, merge program was run in user current directory. Well defined
location is better for scripts. no more need to pass HG_ROOT to merge
program now.
syntax: glob
*.elc
*.orig
*.rej
*~
*.so
*.pyc
*.swp
*.prof
tests/*.err
build
dist
doc/*.[0-9]
doc/*.[0-9].gendoc.txt
doc/*.[0-9].{x,ht}ml
MANIFEST
patches
mercurial/__version__.py
syntax: regexp
^\.pc/