Issue 465 custom blue brand

I have replaced the existing `./custom/brand_example` with the Blue brand.

This includes:

- icons
- splash screens
- custom css
- `inhibitAdvancedLogin`: false
- customAppStrings
- custom templates (still have outstanding issues)

To test this, simply copy the contents of `./custom/brand_example/*` to `./custom/brand/` and run.

Without #468, the app name and package etc will be wrong still... but, yeah... also, the icons and splash probably as the hooks seem to have "SpiderOak" hardcoded as the project name (I have added this to #468).