[Fastly] Add exclusion

Conflicts:
	src/chrome/content/rules/Fastly.xml
[Fastly] Exclude a.prod

Closes https://github.com/EFForg/https-everywhere/issues/657

Conflicts:
	src/chrome/content/rules/Fastly.xml
[Yahoo APIs] Remove yui

yui seems not to be identical to yui-s, and figuring out which parts
work and which don't would require a great deal of effort. So, ToDo.

Closes https://github.com/EFForg/https-everywhere/issues/656
Merge remote-tracking branch 'efforg/4.0' into 4.0