DEV-45809 - Merge Second Life Enterprise changes into viewer 2.x trunk

Includes: DEV-45800, DEV-45803 - Grid Manager
DEV-45804 - SLURL refactor
DEV-45801 - Single username field (for Identity Evolution and SLE Ldap)
Also,
Includes Certificate Management code allowing the viewer to connect to
grids not signed by a well know key (just like any web browser).  Also
contains secure storage for things like passwords.
The security/certificate code is modular with the intention of adding modules
to directly use the operating system facilities for crypto if available.
(that's much more secure than we'll ever be)

Also, refactor of voice to modularize it, and add a diamondware voice module.
CR:  Aimee, James, Lynx, Mani, Karina and a list of thousands