Fix IV check and padding removal.

Fix the calculation that checks there is enough room in a record
after removing padding and optional explicit IV. (by Steve)

For AEAD remove the correct number of padding bytes (by Andy)
(cherry picked from commit be125aa5bae0b6baac526890c835e10378b6df74)
ssl/[d1|s3]_pkt.c: harmomize orig_len handling.
(cherry picked from commit 8545f73b8919770a5d012fe7a82d6785b69baa27)
ssl/s3_enc.c: remove artefact.