Parser rewrite

fixes #145
fixes #148
fixes #141
fixes #67
fixes #147
fixes #94
fixes #77
fixes #122
fixes #79

This commit is a complete rewrite of the core mustache.js file with two
main goals: 1) a major performance boost and 2) better compliance with
the mustache spec.

In order to improve performance templates are pre-compiled to JavaScript
functions. These compiled functions take a view, a partials object, and
an optional callback as arguments. They are cached to prevent
unnecessary re-compilation of an already compiled template. Both of
these enhancements facilitate a generous boost in performance.

A few other notes:

- The mustache.js file is now both browser and CommonJS ready without
  any modification.
- The API exposes two main methods: Mustache.compile and
  Mustache.render. The former is used to generate a function for a given
  template, while the latter is a higher-level function that is used to
  compile and render a template in one shot. Mustache.to_html is still
  available for backwards compatibility.
- The concept of pragmas is removed to conform more closely to the
  original mustache spec. The dot symbol still works to reference the
  current item in an array.
- The parser is much more strict about whitespace than it was before. The
  rule is simple: if a line contains only a non-variable tag (i.e. not
  {{tag}} or {{{tag}}}) and whitespace, that line is ignored in the
  output. Users may use the "space" option when compiling templates to
  preserve every whitespace character in the original template.
- The parser is able to provide detailed information about where errors
  occur when parsing and rendering templates, including the line number
  and surrounding code context.

Conflicts:

	mustache.js

Uses the work done by @nateware in pull request 92. Thanks!

See http://jsperf.com/string-replace-function

package name is now "xulrunner-2.0". We need this to run our tests
in SpiderMonkey.

Thanks drobbins (see https://github.com/janl/mustache.js/pull/113)

Uses a method similar to jQuery.trim in jQuery 1.7.1.

Condition module.exports to make commonjs version work in browsers and no

Narrow rspec dependency

Dot notation support renders 0 and boolean false values as "true"

README: Dereferencing section clarification + describe dot notation

It was confusing to present the concept of dereferencing a nested object and
enumerating over a list in an same example intended to show dereferencing a
nested object. I believe this example illustrates the concept more clearly.