Profiling is added
Options added to GetOverlay function
check if PP can work on current page on page' loading event.
1) check if url is "chrome://*"; 2) check if url is "file://*" and if access to file scheme is allowed
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' into develop
Merge branch 'feature/check-if-pp-can-work-on-current-page' of https://github.com/kroleg/perfectpixel into kroleg-feature/check-if-pp-can-work-on-current-page
Spelling
Merge remote-tracking branch 'origin/develop' into feature/refactoring

Conflicts:
	Extension/background.js
	Extension/manifest.json
	Extension/pp-content.js
	Extension/shared.js
	Extension/storage/pp-storage-filesystem.js
	Extension/storage/pp-storage-localStorage.js
Fixed merge