lua-mode for emacs: added lua-search-documentation

[Jürgen Hötzel <juergen@...>]

Hi,

i revised lua-mode.el from Christian Vogler and added a function for online
documentation look-ups (using html anchors). My changes:

* added interactive function: 
  lua-search-documentation

* added default key-bindings: 
  C-c C-f lua-search-documentation 
  C-c C-l lua-send-buffer

* made lua-default-application, lua-default-command-switches,
  lua-always-show, lua-search-url-prefix and lua-prefix-key customizable
  variables


You can get it here: http://www.hoetzel.info/Hacking/emacs/lua-mode.el
Don't forget to customize your browse-url-browser-function.

Jürgen