0.0.15

This release has a potentially breaking change:

• Hash functions (Sha1, Sha256, Sha384, Sha512) now return a HashResult object instead of string. HashResult can be implicitly converted to a string to help alleviate the pain of this.

Other changes:

• HMAC-SHA functions added (HmacSha1(), HmacSha256(), HmacSha384(), HmacSha512())
• HashResult added with ToString() overloads to support all lowercase (default), uppercase, and base64 strings