fixed minor compiler warnings closure compiler gives

'char' is a reserved word but I am using 'ev.char', so this was changed
to a string based lookup instead.

Fixed to incorrect uses of doc annotations in non-doc comments.
cleaned up 'self' and '_this' usages

Removed all of the pointless uses of '_this' and 'self' from where they
did nothing and were not used.

All instances of '_this' that remained were renamed to 'self', so only
'self' is used now.