add ECIES support in node - not browser
use SJCL AES to get ECIES working in the browser
replace jssha with sjcl - remove jssha dependency
remove underscore dependency to decrease bundle size
remove unused commander dependency
add test to confirm correctness of sha512hmac
rename "rand" to more explanatory "getRandomSeed"
Merge pull request #362 from ryanxcharles/feature/ECIES

add ECIES support