Hack so that the built-in sdk library has the name 'br', rather than
'caplin', even though the name of directory it lives within is still
'caplin' -- we do not plan to address this at present for backwards
compatibility reasons.
Changed how we require the initial 'br.js' file, as the old way doesn't
work now that 'br' is a proper BRJS library.
Removed redundant type cast.