Update for api-change in upstream of vertex-rs.
Merge pull request #275 from csherratt/master

Update for api-change in upstream of vertex-rs.
rename vertex-rs to genmesh
Merge pull request #277 from csherratt/master

rename vertex-rs to genmesh
Ensure everything is tested on travis

`cargo test` does not test dependencies
Fix warnings
Remove SubMesh type

This currently is not used for anything
Merge pull request #281 from bjz/submesh

Remove SubMesh type
Merge pull request #280 from bjz/tests

Ensure everything is tested on travis
flipped plane to match latest genmesh
move to an indexed plane
Merge pull request #290 from csherratt/fix_mesh

Update terrain for latest genmesh
Implemented prototype Light & Heavy batches in a separate module.
Implemented draw_batch
Implemented Batch trait for both light and heavy variants.
Ported the examples to use batches
Added docs, cleaned up the code
Cleaned up old Program trait. Improved comments.
Implemented Graphics class, added HeavyBatch typedef to shader_param, moved examples to the Graphics
Renamed batches to RefBatch and OwnedBatch