Con Cats CURL

The release adds support for base64url String encodings.

base64url is like base64 but has + replaced w/ - and / replaced w/ _. Those are useful when using base64 encoded data within URLs (because + and / have special meanings in them).

It also make base64 decoding more tolerant and will add missing padding (==/=) to please the base64 parser in use.

Other additions:

• Buffer is now a UInt8 Swift Collection
• If Foundation is available, Buffer conforms to ContiguousBytes
• Buffer gained some variants of the Node.js concat function
• ECONNRESET errors in the HTTP Server object are logged as trace to avoid spamming the logs