replaces video download spans with buttons, closes #358

templates/macros.html

@@ -171,7 +171,7 @@ $(function() {
 
 {% macro video_download_btn(videos) %}
 {% if not ismod() %}
-<span class="btn btn-default dropdown-toggle{% if not videos|selectattr('downloadable')|list and not ismod() %} disabled{% endif %}" type="button" data-toggle="dropdown">Download <span class="caret"></span></span>
+<button class="btn btn-default dropdown-toggle{% if not videos|selectattr('downloadable')|list and not ismod() %} disabled{% endif %}" type="button" data-toggle="dropdown">Download <span class="caret"></span></button>
 <ul class="dropdown-menu">
 	{% for v in videos|sort(attribute='formats.prio', reverse=True) if (v.downloadable or ismod() ) %}
 	<li><a href="{{ config.VIDEOPREFIX }}/{{v.path}}">{{v.formats.description}} ({{v.file_size|filesizeformat(true)}})</a></li>