#363 add ExitViaHere

[Kevin Reid]

ExitViaHere was introduced in E-on-CL as a mechanism for easily providing uncalling for emaker-defined objects.

A stub implementation would be putting a stamp-auditor "ExitViaHere" in the scope of emaker evaluations.

Full implementation: http://www.eros-os.org/pipermail/e-lang/2007-March/011944.html