Load a set of predefined labels (#3459)

* Can use a predefined set of labels

* Change UI

* Fix HTML file indentation

* Avoid reading file from other directory (security issue)

* Apply a better fix

* Remove not used variable

* Merge upstream/develop

* Do modifications

* Raname

* remove binding + rename variable

conf/label/Default

@@ -0,0 +1,7 @@
+#ee0701 bug
+#cccccc duplicate
+#84b6eb enhancement
+#128a0c help wanted
+#e6e6e6 invalid
+#cc317c question
+#ffffff wontfix

conf/locale/locale_en-US.ini

@@ -489,6 +489,10 @@ issues.create = Create Issue
 issues.new_label = New Label
 issues.new_label_placeholder = Label name...
 issues.create_label = Create Label
+issues.label_templates.title=Load a set of labels
+issues.label_templates.info=There aren’t any labels. You can click on the "New Label" button above to create one or use a predefined set below.
+issues.label_templates.helper=Select a label set
+issues.label_templates.use=Use this label set
 issues.open_tab = %d Open
 issues.close_tab = %d Closed
 issues.filter_label = Label