Removed compat support for Pike 7.4.

CHANGES

lib/7.4/include/msql.h

lib/7.4/include/mysql.h

lib/7.4/include/postgres.h

lib/7.4/include/simulate.h

lib/7.4/modules/.autodoc

lib/7.4/modules/ADT.pmod/Heap.pike

lib/7.4/modules/Array.pmod

lib/7.4/modules/Crypto.pmod/aes.pmod

lib/7.4/modules/Crypto.pmod/arcfour.pmod

lib/7.4/modules/Crypto.pmod/cast.pmod

lib/7.4/modules/Crypto.pmod/cbc.pike

lib/7.4/modules/Crypto.pmod/crypto.pike

lib/7.4/modules/Crypto.pmod/des.pmod

lib/7.4/modules/Crypto.pmod/des3.pmod

lib/7.4/modules/Crypto.pmod/des3_cbc.pike

lib/7.4/modules/Crypto.pmod/des_cbc.pike

lib/7.4/modules/Crypto.pmod/dsa.pike

lib/7.4/modules/Crypto.pmod/hmac.pike

lib/7.4/modules/Crypto.pmod/idea.pmod