run-tests.py: make tests use same python interpreter as test harness. this is wanted because some tests run python interpreter directly. must use same python interpreter in tests as in main harness or problems will happen because of e.g. different python abi if run-tests.py run with python 2.5 but system python is 2.4. fix is to see if system python is used and is named python. if no, put symlink called python at front of shell search path.

(the addremove command is deprecated; use add and remove --after instead)
adding foo
(the addremove command is deprecated; use add and remove --after instead)
adding bomb
adding a.c
adding dir/a.o
adding dir/b.o
! a.c
! dir/a.o
! dir/b.o
? .hgignore
a.c: unsupported file type (type is fifo)
! a.c
# test absolute path through symlink outside repo
A f
# try symlink outside repo to file inside
abort: ../z not under root