Move SSLv3_*method() functions

Move these functions into t1_clnt.c, t1_srvr.c and t1_meth.c and take
advantage of the existing tls1_get*_method() functions that all the other
methods are using. Since these now have to support SSLv3 anyway we might
as well use the same set of get functions for both TLS and SSLv3.

Reviewed-by: Kurt Roeckx <kurt@openssl.org>