Improves the convenience of the verification of fingerprints.
As ':' are commonly inserted by web browser inside the SHA1 of https web sites, this created false problems with signatures "not matching".
Now, copied and pasted signature from Firefox simply because the verify function will skipped them...
- free up some memory by getting rid of intermediate buffer
- libaxtls: update to 6830d98
- allocate plaintext buffer in two stages: 4*MSS initially, grow to 16k after handshake
- free certificate data after handshake is complete
- preallocate some structures to reduce memory fragmentation
