navigation

Current Behavior

the current DrawerItem passes accessibilityState to Link. this is an invalid attribute for role="link"

Expected Behavior

also exclude accessibilityState from Link in the default DrawerItem

all that really needs to be done is add a line under [this line](https://github.com/react-navigation/react-navigation/blob/0fce8eb2a1e682194d574c65f3366f72e23f2

The button should zoom in to the selected point on the map and show the editor's crosshair at exactly the same place which was selected by the user.

I recently ran into an issue using AMCL, for which I was given this warning message:

[ WARN] [1425574394.999492201]: No laser scan received (and thus no pose updates 
have been published) for 1425574394.999407 seconds.  Verify that data is being published
on the /scan topic.

However, the actual issue was a miscofiguration of the odom_frame_id :
`<param name="odom_frame_id"