Calendar: Fixed deltat calculation and tables.

Also adds some tests.
Don't crash on lazy initialized string buffers.
Test the hash-a-buffer features.
Some smpz tests.
Got rid of fp and sp macros. Define Pike_fp locally in functions.
A few more error cases.
SSL: TLS 1.3 draft 3 does not allow compression.
SSL: Reordered some constants for clarity.

Also removes some redundant stuff from the testsuite.