Adds a libraries attr to directions.
This is so the map and directions elements can share the same API library load
Add example of multiple libs
Merge pull request #58 from GoogleWebComponents/addlibraries

Adds a libraries attr to directions.
Merge pull request #53 from mbykovskyy/stack_overflow_fix

Fixes #52: Only update if lat/long are a numeric type
Zooming in/out the map updates zoom value. Fixes #59.
Removed autocomplete code from demo.
Merge branch 'zoom_update' into develop