Remove outdated legacy crypto options

Many options for supporting optimizations for legacy crypto on legacy
platforms have been removed.  This simplifies the source code and
does not really penalize anyone.
        DES_PTR (always on)
        DES_RISC1, DES_RISC2 (always off)
        DES_INT (always 'unsigned int')
        DES_UNROLL (always on)
        BF_PTR (always on) BF_PTR2 (removed)
        MD2_CHAR, MD2_LONG (always 'unsigned char')
        IDEA_SHORT, IDEA_LONG (always 'unsigned int')
        RC2_SHORT, RC2_LONG (always 'unsigned int')
        RC4_LONG (only int and char (for assembler) are supported)
        RC4_CHUNK (always long), RC_CHUNK_LL (removed)
        RC4_INDEX (always on)
And also make D_ENCRYPT macro more clear (@appro)

This is done in consultation with Andy.

Reviewed-by: Andy Polyakov <appro@openssl.org>