Add `loop` keyword and indentation rule.
Remove `where` from keywords.

It has no special meaning in CoffeeScript.
Add `\` as escape character for block regexes.
Fix: Use Java 6 compatible character classes.

... for Unicode characters in identifiers. (According to ECMA-262
5th Edition.)
Merge pull request #8 from marchaefner/master

Fix Java 6 incompatibility, minor improvements.