Parse boolean string values like git
Parse boolean string values like git

git-config(1) values are strings.  Boolean values are parsed by
lowercasing and comparing against true/false, yes/no, and on/off.

This patch ensures that we parse booleans the same way as git does.

Signed-off-by: Stefan Hajnoczi <484520986196e4a799496429ce8a499eb6488adb@gmail.com>

stefanha/git-publish,stefanha/git-publish