Merge branch 'release/1.21' into develop
fixed issue #11
Merge pull request #14 from kroleg/fix-issue-11

fixed issue #11
CSS compatibility fix
Profiling is added
Options added to GetOverlay function
Comments are refactored to JSDoc format
Comments are refactored to JSDoc format
Thumbnails generation and storage are fully implemented
Thumbnails antialiasing workaround implemented
Old code removed
Merge branch 'feature/layer_thumbnails' into develop
Version is changed to 1.22
Merge branch 'release/1.22'