Remove GeSHi from class and filenames

Authored by TheDJ on May 10 2017, 2:18 PM.

Description

Remove GeSHi from class and filenames

Remove the GeSHi name from filenames and classes where possible. We no
longer actually use GeSHi, and though we cannot rename the extension or
repo atm, we can rename these.

Bug: T164939
Change-Id: I02bc3304d88103c5302f203e788fc73ff20e1050