Added the OpenMote platform and examples. The code compiles and executes
on the target platform. The comments need to be ammended.
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'
Updated with the latest cc2538dk uart configuration files
Merge remote-tracking branch 'upstream/master'.
Updated the OpenMote-CC2538 platform.
Removed the antenna files from the Contiki core.
Merge remote-tracking branch 'upstream/master'
Merge pull request #1 from adamdunkels/peretuset-master

Updated with the latest cc2538dk uart configuration files
Added functions for configuring what antenna to use: external or internal
Initialize and configure the external antenna
Print out RF channel and PAN ID
Use the correct input as button sensor
Merge pull request #2 from adamdunkels/peretuset-master

Add antenna configuration functionality and a small fix to the button sensor.
Merge remote-tracking branch 'upstream/master'
Updated the OpenMote platform configuration and main files.
Merge remote-tracking branch 'upstream/master'.
Removed the antenna-arch.c file since it is no longer needed.
Updated the OpenMote platform.
Merge remote-tracking branch 'upstream/master'.