Copying deriving attributes for the parameter link
Merge pull request #197 from kvark/param

Copying deriving attributes for the parameter link
Remove references of 'retained mode' from README
Add some more targets to the example makefile
Merge pull request #198 from bjz/readme

Remove references of 'retained mode' from README
Merge pull request #200 from bjz/example-makefile

Add some more targets to the example makefile
Fix viewport size on High-DPI displays in examples

Closes #199
Merge pull request #201 from bjz/viewport

Fix viewport size on High-DPI displays in examples
Fix name of gl_init
Merge pull request #205 from tomaka/fix-gl-init

Fix name of gl_init
Add error message for assertion in ProgramHandle::fill_params
Merge pull request #206 from tomaka/error-msg-fill-params

Add error message for assertion in ProgramHandle::fill_params
Fix gl_init events
Merge pull request #207 from tomaka/fix-gl-init-events

Fix gl_init events
Implemented a DrawList trait, its GL backend, added a simple example that will show it off.
First steps at render frontend implementation, bits of framebuffer support.
Cleaned up large chunks of renderer, including the Dispatcher. Implemented mesh binding for the front-end.
Implemented resource deletion, program linking and connection, mesh creation.
Lots of renaming of 'dev' to 'back' to avoid 'device::dev' pattern. Split ProgramMeta into ProgramInfo and the internal name, which are combined into ProgramHandle.
Implemented proper handles for textures, samplers, and surfaces. Deleted all the device and renderer related cruft.