[reSIProcate] Makefile / openssl

[Adam Roach]

I notice that the merge of reflow/recon with main (last May, r7729) 
pulled several rules into the top-level Makefile that seem to rely on a 
custom OpenSSL build:

  7729     contrib/openssl/Makefile:
  7729           cd $(SSL_LOCATION) && ./Configure linux-generic32 
--openssldir=/usr enable-tlsext ${CONFIGURE_ARGS} && $(MAKE) depend
  7729    
  7729     configure_dtls-srtp-openssl: contrib/openssl/Makefile
  7729    
  7729     dtls-srtp-openssl: configure_dtls-srtp-openssl
  7729           cd $(SSL_LOCATION) && $(MAKE)


This causes me concern for two reasons. The first (philosophical) is 
that I thought we were trying to keep additional dependencies 
(especially large ones) from creeping into the tree again. The second 
(practical) is that these rules don't actually work, because there is no 
"openssl" directory under "contrib". Even if there were, these rules 
would work only if $(SSL_LOCATION) were set to point to 
$(ROOT)/contrib/openssl -- this makes the preceding rules very fragile, 
even if openssl is copied into contrib.

I have to admit that I don't fully understand the nature of the code 
that was merged in with r7729. Does it actually require a custom build 
of OpenSSL?

In any case, it appears that we either need to remove these rules, or 
fix them so that they work and aren't brittle. My inclination is to 
remove them, but I'd like to understand why they were added in the first 
place so that I don't break anything.

/a