commandserver: separate initialization and cleanup of forked process Separated _initworkerprocess() and _serverequest() can be reused when implementing a prefork service.

commandserver: unindent superfluous "if True" blocks

pycompat: make pycompat demandimport friendly pycompat.py includes hack to import modules whose names are changed in Python 3. We use try-except to load module according to the version of python. But this method forces us to import the modules to raise an ImportError and hence making it demandimport unfriendly. This patch changes the try-except blocks to a single if-else block. To avoid test-check-pyflakes.t complain about unused imports, pycompat.py is excluded from the test.

run-tests: make --local set --with-chg if --chg is used --local should work with chg as well.

run-tests: allow --local to set multiple attributes This is to make the next patch easier to review. It does not change logic.

chg: add pgid to hgclient struct The previous patch makes the server tell the client its pgid. This patch stores it in hgclient_t and adds a function to get it.

commandserver: send pgid in hello message See the next patches for why we need it.

tests: update test certificate generation instructions Suggestions from Anton Shestakov and Julien Cristau to use -subj and faketime, respectively.