Add clearTags and clearAll methods to ID3

ID3.clearTags(url) removes the cached tags for url.
ID3.clearAll() removes all cached tags.

Related to gh-14
Create LICENSE.md

Fix https://github.com/aadsm/JavaScript-ID3-Reader/issues/9
Add gitignore
Add html example. Update README accordingly
Add FileAPI example
Fix File API example

There's no need to use a FileReader, the FileAPIReader does all that work.
Add missing tags to ID4

comment, tempo, compilation and disc.
Normalize ID4 and ID3 comment structure

ID4 just provides a string for the comment tag while ID3 provides an object with more information.
Provide the ID4 comment string in a similar structure to ID3.
Clarify the origin of the CC license for Base64

It seems that the website has changed the terms of use and the page for the license doesn't exist anymore.
This change points to the original page that mentions the CC using the wayback machine.
This file is only used for the purpose of displaying the cover art in the examples and is not used by the library to extract the tags.
Remove Base64 object and respective file.

This object is only used for example purposes and not by the library itself, since modern browsers already implement window.btoa use this instead on the example page.
Improve example
Add optional FileReader to FileAPIReader.

This allows a user to set an external FileReader instance, therefore providing the ability to reuse the same FileReader instance in serial reads for better memory management.
Merge pull request #25 from dashersw/master

Add optional FileReader to FileAPIReader.
Add .idea to .gitignore

These is the project folder created by WebStorm
Fix README.md examples
Add FileAPI usage to README.md
New dist with FileAPIReader optional FileReader parameter
Places BinaryFile into its own file
Remove binaryajax.js

This is the old version of binaryfile.js
merged upstream/master