Cache to localStorage using If-Modified-Since

[bburky]

Is it possible to make the asset cache backed by localStorage to avoid reloading assets?

The previous discussion in #332 decided to abandon this due to needing server-side support.

However, it is possible to manually set the "If-Modified-Since" header on XMLHttpRequest, avoiding a specialized server:
http://en.wikibooks.org/wiki/JavaScript/XMLHttpRequest#Caching

You will also have to store the value returned in the "Last-Modified" header when loading the asset to send this later in the "If-Modified-Since" header.

That said, this still may be functionality better left to a plugin, but I don't know how hackable the Loader is from plugins.

[photonstorm]

This is an interesting request. It's not something I will do for the 2.0 release, but I have added it to the README file under the Road Map, so it's not forgotten. Going to close this for now though.