Clean up .gitignore
Merge pull request #125 from bjz/gitignore

Clean up .gitignore
Update project structure and ensure examples, tests and docs are built on travis-ci
Merge pull request #126 from bjz/restructure

Update project structure and ensure examples, tests and docs are built on travis-ci
Fix path to deps/khronos-api/gl.xml
Fix #127
Merge pull request #128 from tomaka/fix-127

Fix path to deps/khronos-api/gl.xml
Fix dependency to rust-xml