fix(uiSelectSingle): Tagging without multiple with new tags doesn't works

Tagging in single select is not working which has been testing in latest version of angular. Here, I've just copied working version of code from uiSelectMultiple directive and removed some code which causes the problem.

All the test has been passed. Examples are working fine

Closes angular-ui#1409, angular-ui#890

Author: karthicksundararajan

dist/select.css

@@ -1,7 +1,7 @@
 /*!
  * ui-select
  * http://github.com/angular-ui/ui-select
- * Version: 0.19.5 - 2016-10-24T23:13:59.551Z
+ * Version: 0.18.1 - 2016-07-20T20:40:49.941Z
  * License: MIT
  */
 
@@ -82,16 +82,6 @@ body > .select2-container.open {
     border-bottom-color: #5897fb;
 }
 
-.ui-select-container[theme="select2"] .ui-select-dropdown .ui-select-search-hidden,
-.ui-select-container[theme="select2"] .ui-select-dropdown .ui-select-search-hidden input{
-    opacity: 0;
-    height: 0;
-    min-height: 0;
-    padding: 0;
-    margin: 0;
-    border:0;
-}
-
 /* Selectize theme */
 
 /* Helper class to show styles when focus */
@@ -100,15 +90,10 @@ body > .select2-container.open {
 }
 
 /* Fix input width for Selectize theme */
-.selectize-control.single > .selectize-input > input {
+.selectize-control > .selectize-input > input {
   width: 100%;
 }
 
-/* Fix line break when there's at least one item selected with the Selectize theme */
-.selectize-control.multi > .selectize-input > input {
-  margin: 0 !important;
-}
-
 /* Fix dropdown width for Selectize theme */
 .selectize-control > .selectize-dropdown {
   width: 100%;
@@ -122,17 +107,8 @@ body > .select2-container.open {
 /* Handle up direction Selectize */
 .ui-select-container[theme="selectize"].direction-up .ui-select-dropdown {
     box-shadow: 0 -4px 8px rgba(0, 0, 0, 0.25);
-    margin-top: -2px; /* FIXME hardcoded value :-/ */
-}
 
-.ui-select-container[theme="selectize"] input.ui-select-search-hidden{
-    opacity: 0;
-    height: 0;
-    min-height: 0;
-    padding: 0;
-    margin: 0;
-    border:0;
-    width: 0;
+    margin-top: -2px; /* FIXME hardcoded value :-/ */
 }
 
 /* Bootstrap theme */
@@ -177,15 +153,6 @@ body > .select2-container.open {
   border-bottom-right-radius: 0 !important;
 }
 
-.ui-select-bootstrap .ui-select-search-hidden{
-    opacity: 0;
-    height: 0;
-    min-height: 0;
-    padding: 0;
-    margin: 0;
-    border:0;
-}
-
 .ui-select-bootstrap > .ui-select-match > .btn{
   /* Instead of center because of .btn */
   text-align: left !important;
@@ -261,8 +228,7 @@ body > .ui-select-bootstrap.open {
   border-right: 1px solid #428bca;
 }
 
-.ui-select-bootstrap .ui-select-choices-row>span {
-    cursor: pointer;
+.ui-select-bootstrap .ui-select-choices-row>a {
     display: block;
     padding: 3px 20px;
     clear: both;
@@ -272,21 +238,21 @@ body > .ui-select-bootstrap.open {
     white-space: nowrap;
 }
 
-.ui-select-bootstrap .ui-select-choices-row>span:hover, .ui-select-bootstrap .ui-select-choices-row>span:focus {
+.ui-select-bootstrap .ui-select-choices-row>a:hover, .ui-select-bootstrap .ui-select-choices-row>a:focus {
     text-decoration: none;
     color: #262626;
     background-color: #f5f5f5;
 }
 
-.ui-select-bootstrap .ui-select-choices-row.active>span {
+.ui-select-bootstrap .ui-select-choices-row.active>a {
     color: #fff;
     text-decoration: none;
     outline: 0;
     background-color: #428bca;
 }
 
-.ui-select-bootstrap .ui-select-choices-row.disabled>span,
-.ui-select-bootstrap .ui-select-choices-row.active.disabled>span {
+.ui-select-bootstrap .ui-select-choices-row.disabled>a,
+.ui-select-bootstrap .ui-select-choices-row.active.disabled>a {
     color: #777;
     cursor: not-allowed;
     background-color: #fff;
@@ -307,63 +273,3 @@ body > .ui-select-bootstrap.open {
 .ui-select-container[theme="bootstrap"].direction-up .ui-select-dropdown {
     box-shadow: 0 -4px 8px rgba(0, 0, 0, 0.25);
 }
-
-.ui-select-bootstrap .ui-select-match-text {
-    width: 100%;
-    padding-right: 1em;
-}
-.ui-select-bootstrap .ui-select-match-text span {
-    display: inline-block;
-    width: 100%;
-    overflow: hidden;
-}
-.ui-select-bootstrap .ui-select-toggle > a.btn {
-  position: absolute;
-  height: 10px;
-  right: 10px;
-  margin-top: -2px;
-}
-
-/* Spinner */
-.ui-select-refreshing {
-    position: absolute;
-    right: 0;
-    padding: 8px 27px;
-    top: 1px;
-    display: inline-block;
-    font-family: 'Glyphicons Halflings';
-    font-style: normal;
-    font-weight: normal;
-    line-height: 1;
-    -webkit-font-smoothing:antialiased;
- }
- 
-@-webkit-keyframes ui-select-spin {
-  0% {
-    -webkit-transform: rotate(0deg);
-    transform: rotate(0deg);
-  }
-  100% {
-    -webkit-transform: rotate(359deg);
-    transform: rotate(359deg);
-  }
-}
-@keyframes ui-select-spin {
-  0% {
-    -webkit-transform: rotate(0deg);
-    transform: rotate(0deg);
-  }
-  100% {
-    -webkit-transform: rotate(359deg);
-    transform: rotate(359deg);
-  }
-}
-
-.ui-select-spin {
-  -webkit-animation: ui-select-spin 2s infinite linear;
-  animation: ui-select-spin 2s infinite linear;
-}
-
-.ui-select-refreshing.ng-animate {
-  -webkit-animation: none 0s;
-}