#36 Don't continue lines on some keywords

Certain keywords in lua ca never be part of a multi-line expression.
Check for these keywords in lua-is continuing-statement-p.
add lua-send-defun (a lua-send-proc replacement)

This patch creates a new `lua-send-defun` function which refactors the
existing `lua-send-proc` to use `lua-send-region` instead of its current
implementation (which basically reimplments `lua-send-region` inline.)

It also fixes the issue where `lua-send-proc` would send the _previous_
function when point is at the beggining of the `function` keyword.
lua-send-proc is now an alias to lua-send-defun
Merge remote-tracking branch 'origin/master'
Merge branch 'fix-36' of git://github.com/vhallac/lua-mode
Non-functional refactoring

- reflow lua--builtins initialization code to fit in 80 cols
- reorder lua-mode-syntax-table entries for readability
- alter comments