Doc: Point-and-Click has wrong default and ref to SVG added

Issue 3854

Also made sure that references to Point-and-click are consistent
through lily.scm and external.itely (including TexInfo formatting).

Tried to get some consistency with regard to remove @code{} for
PDF, PS and SVG when referring to the file type or viewer.
Doc: CG - Updated Bug Squad List

As of February 16th 2014
Authors.itexi - Updated Current Developers list

No new people added. But some moved to Previous Developers.

Based on work done in the last 18 months.