Revert "rename git-jira-hook-REST to git-jira-hook"

This reverts commit d62f6cb54d7605ef3ee3879ad92f34986eebaf3d.
Revert "add GPL License file"

This reverts commit d280f229ad40cccf755d2a01a156676fcaf13dc8.
Revert "add new jira hook for REST-API and adapt README to match new hook"

This reverts commit 0d070d0be3a6aa3496395e7016186f2af5836cdd.

Conflicts:
	README
fix errors in README