pull request for port luvi to Lua 5.3

[starwing]

this is the first version for early review, to fix #140.

second commit resolved most warnings I meet when build on windows using VS2015.

To make this, I can check modifies on other platform (I only tested on Windows)

[starwing]

Oops, it seems that I can not checkout a pull request branch that not merged :(

stupid mistable :(

[creationix]

Looks good, just fix the submodules.

[starwing]

@creationix so the missing submodule is luvit/openssl, I submit a pull request to avoid amount of warnings building on VS2015.

[starwing]

I have submit pull request to openssl but it seems not reply, I will try remove openssl update (only for avoid warnings) and commit again :)

[starwing]

lua-openssl need PTHREADS to enable CRYPTO_thread_setup, in theory we can add_definitions(-DPTHREADS) directly, as in rockspecs, but lua-openssl has a bug, I have submit a pull request to up stream, but it's not affect this request (I checked about exists of pthread library)

[creationix]

How can I build luvi using lua? I see the WITH_LUA_ENGINE variable, but am unsure how to pass it in. Also we should probably have the CI configurations build and test both flavors.

[creationix]

If I add -DWITH_LUA_ENGINE=Lua to the tiny target in the Makefile, it seems to try, but fails with:

CMake Error: CMake can not determine linker language for target: lua

[starwing]

? i use this option, let me check it

[starwing]

I have double checked, using:
cmake -DWITH_LUA_ENGINE=Lua ..

build success, but I only checked on Windows, I will check on Linux.

[starwing]

@creationix Sorry for my fall. I found a bug when build with Lua in luv, the default option to build Lua is build a amalg version (lua_one.c), but the path of file lua_one.c is wrong. I have made a pull request on up stream.

but I tested:
cmake -DWITH_LUA_ENGINE=Lua -DWITH_AMALG=OFF ..

it works. After merge from up stream, simply define WITH_LUA_ENGINE works.

I will make a CI pull request in time, and I think luv project need CI for plain Lua, too.

[creationix]

Now that luvi can have multiple lua engines, we should show the engine and version in luvi -v I think.