File: Update comments.
Build: Update bootstrap.
Build, Wiki: Make method anchors more strict.

To avoid naming conflict between static and instance methods.
Build, Wiki: Add markers to static methods and properties.
Build, Wiki: Make 'Table of Contents' less shouty.
Utils, Events: Cleanup a bit.
FileDrop, HTML5: Add destroy method.
FileDrop, HTML5: Simplify destroy method.
FileInput: Add destroy method.
FileInput, HTML5: Destroy can be called more than once, accidentally or not - survive it.
FileInput, HTML4: Add destroy method.
FileInput: When destroying, cleanup associated files as well.