Hide dropdown menu when esc key is pressed.
Fix suggestion when widget created without JSON.

The hidden suggestion text is not always populated and the code should
anticipate that before trying to inspect it.
Fix clear button positioning (single select mode).

Add a containing div for buttons that is floated right so that we can
correctly order the buttons as desired using DOM positioning, etc.
Make single-select clear button key accessible.

Add tab index so that single-select clear button can receive focus and
listen for enter key press. Additionally, click or keypress should place
focus back in the input field.
Allow focus on list filter input.

Show filter input only where necessary, and permit it to be focussed.
Make backspace focus input in single-select mode.

When a single tag is selected in single-select mode, it may still be
focussed and backspace will remove it (as per multi-select mode). In
addition to doing this, the backspace key should cause the input to
receive focus.
Merge pull request #23 from benbasson/fix-hidden-suggestion

Fix suggestion when widget created without JSON.
Merge pull request #24 from benbasson/fix-filter-focus

Allow focus on list filter input.
Merge pull request #25 from benbasson/fix-clear-button

Fix clear button positioning and behaviour.
Merge pull request #26 from benbasson/esc-clear-dropdown

Hide dropdown menu when esc key is pressed.
Added check filter input exists before calling function on it
New version for jquery site and added contributor details