SSLContext internal cleanup + support `SSLContext::METHODS` correctly (#1596)
make sure code actually compiles against JRuby 1.7.x (as well as 1.6.8)
internal cleanup - avoid Utils.checkKind calls as in places used an instanceof check is fine
speed-up SSLSocket OpenSSL::SSL constant resolution + deprecate Utils.newError
change extension's type to a list of <X509Extensions.Extension> and make it final
add a test that checks `OpenSSL::SSL::SSLContext::METHODS` work (fixes #1596)
simplify ASN1's runtime mappings (preparing to avoid leakage) + cleanup the internals