vim: try nodejs and javascript syntax plugins
syntastic: configure javascript checker

Configure syntastic to use the closurecompiler for javascript checking.
Due to the syntastic closurecompiler plugin forces execution of java we
need the jar file here, rather than the /usr/local/bin/closure-compiler
executable.
vim: set closurecompiler executable for syntastic

Switch to my own fork of syntastic for executable support until
scrooloose/syntastic/#1219 is merged.
vim: silent map list motions

Error messages are still shown by the executed command but when a
command is not applicable (like <c-K> on the first item) the mapping is
no longer echoed.