[TxMt] Some refinement to the Smarty bundle

I don't know how many people use the Smarty bundle, but I've made some major improvements. Highlighting now includes support for all assignment, arithmetic, and logical operators. It also properly colors all PHP variables, functions and constants. I also updated the snippets to take advantage of tab stops, and selected text, and includes almost all the options for each function/modifier. Finally, I updated the menu structure.

Also, I patched the HTML and PHP syntax so a block like: {php} $var {/php}

will get properly highlighted as PHP and not as HTML. (Don't apply these patches unless you really use Smarty, since Smarty is by default disabled in the HTML syntax and this will undo that)

Any, comments, suggestions, etc. are welcome.

- Brian