Macros return!

[kvark]

Closes #676
Examples: https://github.com/gfx-rs/gfx_examples/pull/23 (work on rust-beta)
Macros: gfx-rs/gfx_macros#18 (the bye-bye patch)

The change finalizes the port of gfx-rs to rust-beta. Users are advised to use the new macros syntax (check examples PR) and compile on rust beta/stable.

Notes

Practically deprecates gfx_macros. I've lost a lot of blood writing these syntax extensions, but I'd better have a cleaner (and smaller) code base to deal with, so my vote is to let gfx_macros rest in peace.

Current problems (non-critical):

• I had to add pub to all the generated structs and members, which prevents these to be declared inside functions
• We have _r: PhantomData<R> in each shader parameter structure

[ghost]

Looks good to me. I would like a 3rd to look over it.

[cmr]

I'm impressed that the macro is almost as nice to use as the original syntax extension. LGTM.

[bvssvni]

Looks good. I noticed the examples uses underscore in front for the shader parameter x@ _x. Don't know if this is required, but needs some documentation.

[kvark]

Thanks everyone! I'm merging then?

@bvssvni about underscores. 1) they are in tests, not examples. and 2) they are not required, the variables are just unused, so I put an underscore.

[kvark]

I've updated gfx_macros (the bye-bye patch), to avoid forcing everyone to use the new macros just yet. Merging.

[kvark]

Did no one really notice the X-Com reference with gfx::attrib::Floater? 🌍

[ghost]

I was wondering where you got the name from. Shamefully, I have never actually played xcom.