MultiAutoComplete widget

This pull request adds new widget with the following features.

1) Suggestions dropdown will be shown on typing of letters.

2) Suggestions can be selected by mouse or keyborad.

3) If "freeText" option is true, user can edit selected suggestion on double click.

4) Selected suggestion can be removed by on clicking on close icon.

5) If maxOptions is provided in the configuration, user cannot select the suggestions beyond that.

6) Pax/Segement Selection i.e "P1-3" selects Passengers 1, 2 and 3.

7) Error Handling..If freeText is is set to false an error bubble will be shown when entered letters does not match suggestions