Add the crt-royale shader, a full-featured and highly customizable CRT shader

with phosphor mask support, etc.  See the README.TXT for a full
description, a usage overview, and Frequently Expected Questions
regarding performance, compilation errors, etc.  The default settings
are tuned for quality, configurability, and successful compilation on
both nVidia and non-nVidia hardware, but additional user-settings.h
files are included in a subdirectory for quickly testing much faster
option sets.  Have fun. :)

(This pull request also includes supporting commits for the blurs
and include directories.)