Follows-up 6bdb0c68c.
* Ensure consistent use of '$' over 'jQuery'
(already followed in the code, but not previously ensured.)
* Prevent future issues similar to those fixed by 6bdb0c68c, by
disabling inheritence from any parent directories.
Change-Id: Ifa2cb20b224403ad4c6137e0f690fa4233dd942e
It seems that this setting was being inherited from MediaWiki core
until recently, but now it's not.
Change-Id: Ibd38d7340d5281a6fd4e6d54eb9f7ef72e3df107
