serve video files using the HTML5 video tag (#418)

* serve video files using the HTML5 video tag

* lint fix: add comment to IsVideoFile

conf/locale/locale_en-US.ini

 file_view_raw = View Raw
 file_permalink = Permalink
 file_too_large = This file is too large to be shown
+video_not_supported_in_browser = Your browser doesn't support HTML5 video tag.
 
 editor.new_file = New file
 editor.upload_file = Upload file

modules/base/tool.go

 func IsPDFFile(data []byte) bool {
 	return strings.Index(http.DetectContentType(data), "application/pdf") != -1
 }
+
+// IsVideoFile detectes if data is an video format
+func IsVideoFile(data []byte) bool {
+	return strings.Index(http.DetectContentType(data), "video/") != -1
+}

routers/repo/view.go

 
 	case base.IsPDFFile(buf):
 		ctx.Data["IsPDFFile"] = true
+	case base.IsVideoFile(buf):
+		ctx.Data["IsVideoFile"] = true
 	case base.IsImageFile(buf):
 		ctx.Data["IsImageFile"] = true
 	}

templates/repo/view_file.tmpl

 				<div class="view-raw ui center">
 					{{if .IsImageFile}}
 						<img src="{{EscapePound $.RawFileLink}}">
+					{{else if .IsVideoFile}}
+						<video controls src="{{EscapePound $.RawFileLink}}">
+							<strong>{{.i18n.Tr "repo.video_not_supported_in_browser"}}</strong>
+						</video>
 					{{else if .IsPDFFile}}
 						<iframe width="100%" height="600px" src="{{AppSubUrl}}/plugins/pdfjs-1.4.20/web/viewer.html?file={{EscapePound $.RawFileLink}}"></iframe>
 					{{else}}