Add formula for Tegh 0.2.0 (Tea, Earl Grey, Hot)

Adding a new formula for tegh (Tea, Earl Grey, Hot), a command line client to remotely monitor and control 3D printers running Prontserve.

Tegh has not yet reached an initial release but is quite useable none the less so this formula is head-only for the time being.

This new pull request includes the Tegh 0.2.0 release where the previous pull request ( https://github.com/mxcl/homebrew/pull/20454 ) did not.