Fix --blacklist when --jobs > 1 in run_tests.py. The options parsing logic replaces the options.blacklist initial value, a list of filenames, with a dict of test names to filenames. When runchildren rebuilds the command line to launch child processes the dict is flattened and provided as a malformed argument when a filename is expected. Fix is to remove the blacklist option from child invocations since the filtering is handled in the parent anyway.

merge with stable

run-tests.py: reset env variables set by hooks

checklink: use an explicit prefix for the temporary file

revlog: factor out _maxinline global. This lets us change the threshold at which a *.d file will be split out, which should make it much easier to construct test cases that probe revlogs with a separate data file. (issue2137)

fix test-pull after 468876bc3885

merge with stable