Clean up non-fatal error handling - we know which error numbers we have
defined.

ok miod@ beck@
Some software expects RAND_status() to return 1 for success, so always
return 1 in the arc4random backend because there is no possible error
condition.  Unbreaks lynx, git and friends.

ok miod@ dcoppa@
Make this byzantine horror a shell of it's former self by stubbing the
functions. The ability to set the debug mem functions died with mem.c,
but some of the rest of this is still exposed API so we can't delete it..
yet...
ok tedu@
More KNF.
Kill the bogus "send an SSLv3/TLS hello in SSLv2 format" crap from
the SSLv23_* client code.  The server continues to accept it.  It
also kills the bits for SSL2 SESSIONs; even when the server gets
an SSLv2-style compat handshake, the session that it creates has
the correct version internally.

ok tedu@ beck@