added Script.getMultiSigInfo as easy helper to return information about a multisig script
updated naming for getMultiSigInfo
Merge pull request #290 from blocktrail/getMultiSigInfo

added Script.getMultiSigInfo
update key signing to use new SecureRandom

...and throw an error if you try to use the old, non-secure random number
generator.
up version to 0.1.15
Merge tag 'v0.1.15'

Conflicts:
	package.json