intro/outro padding and node module support

 - intro.js and outro.js provide a proper closure for Saber variable
   definitions. Any global variable in saber module will not pollute
   the namespace.

 - Support for exporting Saber as a node package, independent of
   dom.

Signed-off-by: Rohan Jain <crodjer@gmail.com>
Remove half-baked errors system implementation

Signed-off-by: Rohan Jain <crodjer@gmail.com>