Merge pull request #17 from dsheets/request_control

Request control
allow hierarchical cookie names; check for (some) invalid names
fix backup date
backup properly in presence of hierarchical cookie names
actually backup properly
really actually backup properly
Add `Token.delete` function
Add `Github_cookie_jar.delete` function; disallow more cookie names
Add git jar revoke command; factor common CLI args; fixup show table; bump minor version
Update CHANGES with new features etc
Merge pull request #19 from dsheets/biscuit-crock

Biscuit crock 1.1
Merge branch 'master' of https://github.com/avsm/ocaml-github into request_control