Refactoring `AttributeBuffer` for the new separate API approach.
WIP on refactoring the APIs.

Moving base functionality into the `macrogl` source directory.
Instead of having WebGL and OpenGL commons in `macrogles` source
directory, we now have `macrogl` source directory.
Additional functionality is moved into `macroglex` -- the extended
API layer.
I think this is more natural.

Then, compute shader functionality (OpenGL 4.3) is moved into
`macroglex` source folder. You can see that `AttributeBuffer`'s
`computing` calls now use `Macroglex` API -- the extended API layer.

Refactoring `MeshBuffer`s to the new API model.
Refactoring `FrameBuffer` and `Program`.
Fix `Program` and `FrameBuffer` imports.
Matrix refactored.
`RenderBuffer` refactored.
Refactored `Texture`.
Refactored the remainder of the `macrogl` package.
Merge branch 'master' of github.com:storm-enroute/macrogl
Avoiding clash in the source code artifact for 2 same filenames.
Adding the missing apply in macro expansion.
Adding another missing apply in `macroApplication` match.
Fixing texture issues with texture not being bound in the ctor.

Also, renaming `Buffer` to `Data` -- with `collection.mutable.Buffer`,
`java.nio.Buffer` and `AttributeBuffer`s in OpenGL,
no need to add further confusion.
Update README.md
Merge pull request #27 from axel22/master

Fixing texture issues with texture not being bound in the ctor.
Fixing stuff we broke with the refactoring.
Add an example of transform feedback.
Add an example of a buffer texture.
Return value from `*InfoLog` methods.
Specify return type explicitly.