Adding $'s to variables.

Moving towards PHP syntax (#19)
Foreach: from in-syntax to as-syntax

Brings us closer to PHP-likeness (#19)
Cleanup

There still was a line that was useless since the variable it wrote to was
overwritten later in the same function without any use in between.
Fixes parser bug

Something went wrong when there was a combination of whitespace and
endforeach which the parser didn't like. All that needed to be added was a
single asterisk.
Moved to PHP (alternate) control structure syntax

Like: "<: if: :>A<: endif :>"

Considers if, else, for and foreach (and allows any capatalization for
true and false constants).

Changes:

- if, else, for and foreach now erquire a colon at the end
- white space between end and for/foreach/if is no longer allowed (in
  enders)
- Capitalization of these words (and boolean constants) no longer matters

This is one more step towards #19