Ecurve and non-custom crypto-browserify

Since the latest browserify release (which we are using since https://github.com/bitcoinjs/bitcoinjs-lib/commit/6dbf00f7acb08ed8d6b5450d0154803df616a179), we no longer need to specify a custom version of crypto-browserify.

Also, ecurve was bumped to `1.0.0`, no reason not to use that, given the only changes since `0.10.0` was removed support for the `secp224r1` curve, and a typo.