added tagmanager publicMethod 'extractTagsFromString'

[bmaso]

• bmaso needed ability to parse multiple tags at once specifically when users "paste" text w/ multiple tags into tm-input
• Created new tagmanager public method extractTagsFromString: returns an array of the tags present in any given string as if text had been typed in one character at a time
  • splits input string on tag delimiters
  • trims whitespace of each tag
• External code can then use extractTagsFromString and pushTag methods in conjunction to push multiple tags at once, e.g. as part of a "paste" event handler:

$(".tm-input").on("paste", function(e) {
  setTimeout(function() {
    //...compute tags present in the pasted text...
    var text = $(".tm-input").val();
    tagsArr = $(".tm-input").tagsManager("extractTagsFromString", text);

    //...clear input element contents...
    $(".tm-input").val('');

    //...push tags...
    for(var ii=0; ii<tagsArr.length; ii++) {
      $(".tm-input").tagsManager("pushTag", tagsArr[ii]);
    }
  }, 0);
});