Add dependency to examples/simple.scm
Remove eval, syntax definitions in defpipeline

And syntax definitions in defshader.
Added new way of informing defpipeline about uniforms, in absence
of the eval.
Add examples/basic.scm, update readme example
defpipeline, defshader  -> define-thing
Update readme
Add automatic render function generation
Fix glls-render for use in modules

Remove eval
Update examples for glls-render
Simplify input parsing
Fix uniform def for previously defined shaders