[OXT-10] v2

Applying this to an existing tree will require some minor mods:

OPENXT_GIT_MIRROR needs to be re-defined to github.com/OpenXT instead of git://github.com/OpenXT

OPENXT_GIT_PROTOCOL needs to be defined as "git"|"https"

OPENXT_BRANCH needs to be defined as "master"

You can make the mods in your local.conf as well as want to edit your .config for future use.