Support `getRouteMap(function (annotations) {...})` signature

This adds support to `getRouteMap()` to accept a filter function, making
it support the same signatures as `findAll()`.

Fixes #4
Reduce complexity of `getRouteMap()` by removing the early filtering
Apply all args from getRouteMap() to findAll()
Merge branch 'get-route-map-fn'

Conflicts:
	index.js