Ensures tags have adequate margin when tag list grows to span multiple lines.
Updates tag remove to use the more elegant 'multiplication' symbol for its icon.
Fixes bug where input length was based on value length instead of placeholder length.
Adds an 'x' button within the far right of the input to remove all selected tags.
Adds a new sourceTags typeahead option that will display all available typeahead.source tags below the input when it receives focus. These source tags may be clicked to be added to the list of selected tags.