Bug 1090843 - Improve the time required for being interactive

- Delay load the modules for loading hardware information required in the module of the root panel.
- Delay the use of query selectors in the init function of the root panel.
- Remove redundant setTimeouts in the panel navigation process.
- Some modules required in main.js are delay loaded.
l10n is not a heavy operation, but we really try to make sure that it blocks the firstPaint :)

I believe that this is the right moment to fire the event. (vs. the app-visually-complete event I commented on earlier)