* Leaner, meaner crypto module; now with HMAC
Based on my testing, mbedtls pulls in all its algorithm regardless of
whether the NodeMCU crypto module was using them or not. As such, the
space savings from omitting algorithms were only in the tens of bytes.
By switching to using the mbedtls generic message digest interface, the
crypto module itself could be shrunk in size and complexity. Despite
adding support for HMAC on all algorithms (plus including RIPEMD160),
this version is 330 bytes smaller.
* Updated crypto module docs.
* Removed superfluous brackets in crypto docs.
Copy-paste considered harmful... >.>