Fix inconsistent parenthesis whitespace.

index.js, lib/addresses/osm.js
  -Add a space after `(` and before `)` where appropriate, for
  style consistency.
Define testImports(), make main entry point.

index.js
  -Define `testImports()`, now the module's main entry point,
  which simulates ultimate usage better than `handleUserInput()`
  (these will be scripted imports after all).

lib/addresses/tiger.js
  -Add a skeleton module for the TIGER importer.