Align the header logo vertically.

Override the bootstrap css to properly vertically align the logo. 
This may or may not be the correct position to override the css properly.

I was unable to build and test myself from the readme server.hxml throws...

```
/usr/lib/haxe/lib/ufront-mvc/1,0,0-rc,2/src/ufront/web/HttpError.hx:19: characters 30-43 : Unknown identifier : InternalError
/usr/lib/haxe/lib/ufront-mvc/1,0,0-rc,2/src/ufront/web/Controller.hx:75: characters 2-11 : Build failure
```