use lua_pushliteral for string-literals.
bugfix: we did not check allocation failures while compiling the pattern for tcpsock:receiveuntil(). thanks Tatsuhiko Kubo for the patch in #407.
Merge pull request #408 from cubicdaiya/issues/use_luapushliteral

use lua_pushliteral for string-literals.
tests: fixed a test case to reflect latest change in ngx_set_misc.
bugfix: tcpsock:sslhandshake() incorrectly returned failures when the SSL handshake operation succeeded immediately.