Use `strip-json-comments` to allow comments in JSON config files.

Large JSON-formatted config files can get very unwieldy without comments,
and feature parity with INI-formatted comments is a nice bonus.

Incidentally, this also verifies the "local" .APPNAMErc pattern.
Merge branch 'strip-json-comments' of github.com:evocateur/rc
0.4.0