src/javascript/core/utils/Mime.js
function (mimeData) {
		var items = mimeData.split(/,/), i, ii, ext;

		for (i = 0; i < items.length; i += 2) {
			ext = items[i + 1].split(/ /);

			// extension to mime lookup
			for (ii = 0; ii < ext.length; ii++) {
				mimes[ext[ii]] = items[i];
			}
			// mime to extension lookup
			extensions[items[i]] = ext;
		}
	}
function (mimeData) {
		var items = mimeData.split(/,/), i, ii, ext;

		for (i = 0; i < items.length; i += 2) {
			ext = items[i + 1].split(/ /);

			// extension to mime lookup
			for (ii = 0; ii < ext.length; ii++) {
				mimes[ext[ii]] = items[i];
			}
			// mime to extension lookup
			extensions[items[i]] = ext;
		}
	}
Parses mimeData string into a mimes and extensions lookup maps. String should have the
following format:

application/msword,doc dot,application/pdf,pdf, ...

so mime-type followed by comma and followed by space-separated list of associated extensions,
then comma again and then another mime-type, etc.

If invoked externally will replace override internal lookup maps with user-provided data.

@method addMimeType
@param {String} mimeData