test-check-code-hg: drop manual check of non-.py scripts

test-check-code-hg: use test-repo check

check-code: look at shebang to identify Python scripts

tests: use locate to find files for pyflakes check Based on a suggestion by Yuya Nishihara

merge with stable

Added signature for changeset 2195ac506c6a

Added tag 3.0 for changeset 2195ac506c6a

revset: directly use __contains__ instead of a lambda We get rid of lambda in a bunch of other place. This is equivalent and much faster. (no new timing as this is the same change as three other changesets)