run-tests: include testdir in $PATH so tests easily can use helper tools The testdir is already added to $PYTHONPATH - I think it makes sense and is convenient to add it to $PATH too. The following binaries are invoked from tests using full path with $TESTDIR/ - they can now be used without specifying path: dumbhttp.py dummyssh filterpyflakes.py generate-working-copy-states.py get-with-headers.py hghave histedit-helpers.sh killdaemons.py md5sum.py notcapable printenv.py readlink.py revlog-formatv0.py run-tests.py svn-safe-append.py svnxml.py tinyproxy.py