convert: use subprocess for all commandline calls Avoid mixing popen and subprocess calls, it simplifies the command line generation and quoting issues with redirections. In practice, it fixes the subversion sink on Windows and probably helps with monotone and darcs sources.

convert: make commandline.limit_arglist private, simplify

largefiles: adjust localstore to handle batch statlfile requests (issue3583) This fixes a traceback when pushing to a local repo which started with 9e1616307c4c.