libcrypto provides certain optimized assembler functions which
unfortunatly are non-pic. Therefore this asm code is removed
and libcrypto is build with -DOPENSSL_NO_ASM.
Because the asm code is not needed anymore, its generation is
also removed from openssl.mk.
import-libssl.mk was also added because it is essential for building
programs which depend on libssl.
Fixes#291.
Fixes#294.
