Update to bootstrap 4

Thanks to @adeeb1 and others who have opened pull requests on the official repo.

Author: wradstok

dist/css/bootstrap-multiselect.css

@@ -1 +1,88 @@
-span.multiselect-native-select{position:relative}span.multiselect-native-select select{border:0!important;clip:rect(0 0 0 0)!important;height:1px!important;margin:-1px -1px -1px -3px!important;overflow:hidden!important;padding:0!important;position:absolute!important;width:1px!important;left:50%;top:30px}.multiselect-container{position:absolute;list-style-type:none;margin:0;padding:0}.multiselect-container .input-group{margin:5px}.multiselect-container .multiselect-reset .input-group{width:93%}.multiselect-container>li{padding:0}.multiselect-container>li>a.multiselect-all label{font-weight:700}.multiselect-container>li.multiselect-group label{margin:0;padding:3px 20px;height:100%;font-weight:700}.multiselect-container>li.multiselect-group-clickable label{cursor:pointer}.multiselect-container>li>a{padding:0}.multiselect-container>li>a>label{margin:0;height:100%;cursor:pointer;font-weight:400;padding:3px 20px 3px 40px}.multiselect-container>li>a>label.checkbox,.multiselect-container>li>a>label.radio{margin:0}.multiselect-container>li>a>label>input[type=checkbox]{margin-bottom:5px}.btn-group>.btn-group:nth-child(2)>.multiselect.btn{border-top-left-radius:4px;border-bottom-left-radius:4px}.form-inline .multiselect-container label.checkbox,.form-inline .multiselect-container label.radio{padding:3px 20px 3px 40px}.form-inline .multiselect-container li a label.checkbox input[type=checkbox],.form-inline .multiselect-container li a label.radio input[type=radio]{margin-left:-20px;margin-right:0}
+span.multiselect-native-select {
+    position: relative
+}
+
+span.multiselect-native-select select {
+    border: 0!important;
+    clip: rect(0 0 0 0)!important;
+    height: 1px!important;
+    margin: -1px -1px -1px -3px!important;
+    overflow: hidden!important;
+    padding: 0!important;
+    position: absolute!important;
+    width: 1px!important;
+    left: 50%;
+    top: 30px
+}
+
+.multiselect-container {
+    position: absolute;
+    list-style-type: none;
+    margin: 0;
+    padding: 0;
+    z-index: 5000;
+}
+
+.multiselect-container .input-group {
+    margin: 5px
+}
+
+.multiselect-container .multiselect-reset .input-group {
+    width: 93%
+}
+
+.caret {
+    display: inline-block;
+    width: 0;
+    height: 0;
+    margin-left: 2px;
+    vertical-align: middle;
+    border-top: 4px solid;
+    border-right: 4px solid transparent;
+    border-left: 4px solid transparent;
+}
+
+/* Make the select all option is centered. */
+li.multiselect-all > div.form-check {
+    padding-left:0px;
+    display: flex;
+}
+
+li.multiselect-all > div.form-check > label.checkbox {
+    max-width: 45%;
+    color:black;
+}
+
+/* Left align optgroups */
+.multiselect-container>li.multiselect-group label {
+    padding-left:0.25em;
+    font-weight: 700;
+    /* display: inline; */
+}
+
+.multiselect-container>li.multiselect-group-clickable label {
+    cursor: pointer
+}
+
+.multiselect-container>li>div>label {
+    margin: 0;
+    width: 100%;
+    height: 100%;
+    cursor: pointer;
+    font-weight: 400
+}
+
+.btn-group>.btn-group:nth-child(2)>.multiselect.btn {
+    border-top-left-radius: 4px;
+    border-bottom-left-radius: 4px
+}
+
+.form-inline .multiselect-container li a label.checkbox input[type="checkbox"],
+.form-inline .multiselect-container li a label.radio input[type="radio"] {
+    margin-left: -40px;
+    margin-right: 0
+}
+
+.multiselect-filter {
+    padding-right: 1rem
+}