Misc fixes in util/mk1mf.pl

mk1mf was wondering about the options no-heartbeats and
no-crypto-mdebug-backtrace, so we add option hooks them.  They only
need to become OPENSSL_NO_ macros in opensslconf.h, so nothing
additional needs to be done.

Also, add "-DOPENSSL_PIC" when shared libraries are produced.

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