bigi: remove unnecessary comments
package: adds jshint
bigi: remove unused variables
bigi: beautified

Used js-beautify, indent 2 spaces, max 2 new-lines, no wrap with space
before conditionals.
package: fix no reporter found
bigi: remove semi-colons
bigi: restrict constructor
bigi: remove nbi alias for new Bigi
tests: rename bigi-convert to convert
LICENSE: fix license formatting
tests: merge tests from BN.js
Merge pull request #9 from dcousens/cleanup

Cleanup and basic tests