`cmsgpack.safe` module and some fixes

Merge with https://github.com/puppi. (#16)
 * Added support `+-inf`
 * Added stream support

@puppi i update only `lua_cmsgpack.c` because i want minimum diff with current maseter.

Lua 5.2 compatibility.
 * Global variable (`cmsgpack`) creates only on Lua 5.1
 * See `test_global`

Add. `cmsgpack.safe` module.
 * This module do not raise error but just return error code.
 * See `test_error`/`test_safe`.

Fix. Some arrays do not detect as array.
 * See `test_array`.

Add .travis.yml  file