Variable cleanups; Unused vars, Typo'd vars, and excess code blocks

[dd32]

I've just done a cleanup of many variables which were only used once, Some of these turned out to be typo's, and some code blocks were entirely ignored in the rest of the function.

This ticket is to act as a point of contact for any issues which arrise from this changeset.

[dd32]

(In [13242]) Variable Cleanup, Unused variables, Typo'd variables, unused code blocks. Fixes #12299

[dd32]

Seems my PHP client has sliped in a few case changes of 'onclick' to 'onClick' again in that changeset which went unnoticed in the Diff.