Added highlighting in Emacs for ${...} variables
Removed tab and added . in variable name regexp
Merge pull request #772 from drbo/syntax_bugfix

Added highlighting in Emacs for ${...} variables
no subshell

don't need subshell to send stderr to /dev/null
Don't leave lone closing parens.
Use double semicolon comments.
Reindent ninja-mode.el using Emacs.

Emacs knows best how to indent Emacs Lisp.
Use quasi-quoting instead of list+cons.
Set comment-start buffer-locally, not globally.
Set up a proper syntax table for ninja-mode.

Since quotes are not meant to be treated as string delimiters,
the syntax table is the place to tell Emacs so.

This also means syntactic fontification can be reenabled and the
font-lock keyword entry for comments removed.
Correctly recognize comments.
Remove unnecessary regexp group.
Don't use dotted list syntax unless necessary.
Avoid putting properties past the end of the buffer.
Correctly recognize a comment if the previous line is a comment ending in $.
Add a Emacs 24 requirement.

Only Emacs >= 24 has prog-mode.
Use lexical-binding.

There's no reason not to use lexical-binding when supporting only
Emacs 24+. Its semantics are just that much saner.