Log Message:
Update to 20130419:

* highlight hash-bang line as comment

* make lua-mode-hook editable via customize

* fix several indentation bugs & quirks

* fix lua-send-proc not to send previous function when point is at the beginning \ 
of a function

* derive lua-mode from prog-mode for Emacs24

* add font-locking for builtins and numeric constants

* fix a bug causing exponential complexity in a keyword matching regexp

* add more unindentation cases for block-closing tokens

* improve multiline highlighting via font-lock-syntactic-keywords
   This should make font-locking of multiline literals more fluent & stable. And
   it becomes customizable via standard font-lock configuration

* properly fontify variable definitions in 'local ...' & 'for ...'
   Also, perform some basic syntax verification in those lines. Multi-line
   constructs not supported yet.

* fix indentation for blocks starting on continued lines
     local foo =
        {
           bar,
           baz
        } ^
           1. these lines should be indented properly now
     ^
     2. the following lines should be unindented properly now

* extend imenu-generic-expression
   Now it matches 'foo = function(...)' function definitions