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

Our current day/night mode settings are misleading:

1. Auto <!-- Automatic for navigation mode only
2. On <!-- Always on
3. Off <!-- Always off

Users expect, that "Auto" will change the map theme also. The dark theme for maps is opinionated. Some people, including me, just doesn't like maps in the dark mode. However, the dark mode is really required during navigation in or

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"