Use client-side caching for webui

[lildadou]

I find that the web page of deluge-web is very long to load. The main reason is that the JavaScript? files are downloaded each page opening. As I use nginx in front, I added a rule that queries on static files (ico, css, js, gif, jpg, png) was treated with an additional header who caching response on the client side (Cache-Control).

• Context : min/max (size)
• With forced cache rule : 1,97s/2,11s (3,89KB transferred)
• Without forced cache rule : 13,69s/13,72s (850,99KB transferred)
• First load (no client-side caching) : 14,72s/15,20s (859,72KB transferred)

​Biggest files of web-ui

HTTP response example:

GET /js/ext-all-debug.js HTTP1.0

HTTP1.0 200 OK
Date: Tue, 13 Mar 2012 14:35:15 GMT
Content-Length: 642823
Content-Encoding: gzip
Content-Type: application/javascript
Server: TwistedWeb/11.0.0