add lsl mode

based on C/C++ mode and the LSL Wiki as of 2013-01-27
fix up/down arrow handling when selection is present
Merge pull request #1268 from wcandillon/master

XQuery Mode bug fixes.
Merge pull request #1254 from nemurimasu/master

LSL support
fix #1266: Scroller is collapsed when ace initialized with empty value
fix #1250: remove obsolete documentation for loadMode event
add more tests for ruby highlighting
add highlighting for new and :: in php mode
tweak mode converter
restore defferedCall
Merge pull request #1272 from ajaxorg/virtual_renderer

fix #1266: Scroller is collapsed when ace initialized with empty value
fix editor getting stuck in drag mode
fix name handling in bindkey
modify navigateUp/Down behavior only if selection is multiline
cleanup
fix moving lines with folds
allow toggling fold widget when editor isn't focused
keep folds while dragging text inside the editor
cleanup
allow multiple selections with shared edges