Working build script
Ignore build and package directories
Rename to make it explicitly WPEngine specific
Clarify the code comments
Merge branch 'master' into feature/build-wpengine

* master:
  Better docs, different handling of build branch…
  Ooops, reinstate `REPO_SSH_URL`
  Added GPL declaration to readme
  I hereby GPL this project
  More detailed comments on generating fingerprints for the `known_hosts` file.

Conflicts:
	build.sh