Add a bulk delete button

I needed this in my day job, but think we need to do better on bulk
operations

core/ui/AdvancedSearch/FilterButtons/delete.tid

@@ -0,0 +1,26 @@
+title: $:/core/ui/AdvancedSearch/Filter/FilterButtons/delete
+tags: $:/tags/AdvancedSearch/FilterButton
+
+<$reveal state="$:/temp/advancedsearch" type="nomatch" text="">
+<$button popup=<<qualify "$:/state/filterDeleteDropdown">> class="tc-btn-invisible">
+{{$:/core/images/delete-button}}
+</$button>
+</$reveal>
+
+<$reveal state=<<qualify "$:/state/filterDeleteDropdown">> type="popup" position="belowleft" animate="yes">
+<div class="tc-block-dropdown-wrapper">
+<div class="tc-block-dropdown tc-edit-type-dropdown">
+<div class="tc-dropdown-item-plain">
+<$set name="resultCount" value="""<$count filter={{$:/temp/advancedsearch}}/>""">
+Are you sure you wish to delete <<resultCount>> tiddler(s)?
+</$set>
+</div>
+<div class="tc-dropdown-item-plain">
+<$button class="tc-btn">
+<$action-deletetiddler $filter={{$:/temp/advancedsearch}}/>
+Delete these tiddlers
+</$button>
+</div>
+</div>
+</div>
+</$reveal>

core/wiki/tags/AdvancedSearchFilterButton.tid

@@ -0,0 +1,2 @@
+title: $:/tags/AdvancedSearch/FilterButton
+list: $:/core/ui/AdvancedSearch/Filter/FilterButtons/dropdown $:/core/ui/AdvancedSearch/Filter/FilterButtons/clear $:/core/ui/AdvancedSearch/Filter/FilterButtons/export $:/core/ui/AdvancedSearch/Filter/FilterButtons/delete

themes/tiddlywiki/vanilla/base.tid

@@ -1315,6 +1315,11 @@ html body.tc-body.tc-single-tiddler-window {
 	padding: 0px 10px 0px 10px;
 }
 
+.tc-drop-down .tc-dropdown-item-plain,
+.tc-block-dropdown .tc-dropdown-item-plain {
+	padding: 4px 14px 4px 7px;
+}
+
 .tc-drop-down .tc-dropdown-item,
 .tc-block-dropdown .tc-dropdown-item {
 	padding: 4px 14px 4px 7px;