`http.ServeFile/ServeContent` handles `If-xxx`, `Content-Length`, `Range` and `Etag` correctly After this PR, storage files (eg: avatar) could be responded with correct Content-Length.  | 
			||
|---|---|---|
| .. | ||
| httpcache.go | ||
| httpcache_test.go | ||
				
					
						
							`http.ServeFile/ServeContent` handles `If-xxx`, `Content-Length`, `Range` and `Etag` correctly After this PR, storage files (eg: avatar) could be responded with correct Content-Length.  | 
			||
|---|---|---|
| .. | ||
| httpcache.go | ||
| httpcache_test.go | ||