(#1554) Add support for all common compressions (write and read)

- Remove the context.Context interface and export the *context, the iris.Context now points to the pointer\nSupport compression and rate limiting in the FileServer\nBit of code organisation


Former-commit-id: ad1c61bf968059510c6be9e7f2cceec7da70ba17

_examples/file-server/basic/main.go

@@ -23,7 +23,7 @@ func newApp() *iris.Application {
 		// if end developer does not managed to handle it by hand.
 		IndexName: "/index.html",
 		// When files should served under compression.
-		Gzip: false,
+		Compress: false,
 		// List the files inside the current requested directory if `IndexName` not found.
 		ShowList: false,
 		// If `ShowList` is true then this function will be used instead of the default one to show the list of files of a current requested directory(dir).

_examples/file-server/file-server/main.go

@@ -54,7 +54,7 @@ func main() {
 	filesRouter := app.Party("/files")
 	{
 		filesRouter.HandleDir("/", uploadDir, iris.DirOptions{
-			Gzip:     false,
+			Compress: true,
 			ShowList: true,
 
 			// Optionally, force-send files to the client inside of showing to the browser.

_examples/file-server/file-server/views/dirlist.html

@@ -83,7 +83,11 @@
             {{ range $idx, $file := .Files }}
             <tr>
                 <td>{{ $idx }}</td>
+                {{ if $file.Download }}
+                <td><a href="{{ $file.Path }}" title="{{ $file.ModTime }}" download>{{ $file.Name }}</a></td> 
+                {{ else }}
                 <td><a href="{{ $file.Path }}" title="{{ $file.ModTime }}">{{ $file.Name }}</a></td>
+                {{ end }}
                 {{ if $file.Info.IsDir }}
                 <td>Dir</td>
                 {{ else }}