run-tests.py: execute hghave with same env vars as ones for actual tests Before this patch, "run-tests.py" executes "hghave" process without any modifications for environment variables, even though actual tests are executed with LC_ALL, LANG and LANGUAGE explicitly assigned "C". When "run-tests.py" is executed: - with non-"C" locale environment variables on any platforms, or - without any explicit locale environment setting on Windows (only for "outer-repo" feature using "hg root") external commands indirectly executed by "hghave" may show translated messages. This causes incorrect "hghave" result and skipping tests, because some regexp matching of "hghave" expect external commands to show un-translated messages. To prevent external commands from showing translated messages, this patch makes "run-tests.py" execute "hghave" with same environment variables as ones for actual tests. This patch doesn't make "hghave" execute external commands forcibly with LC_ALL, LANG and LANGUAGE explicitly assigned "C", because changing "run-tests.py" is cheaper than changing "hghave": - "os.popen" should be replaced by "subprocess.Popen" or so, and - setting up environment variables should be newly added