In both cases, the ABI is now obtained by executing "uname -m" on the
device and perfroming a mapping from the returned machine architecture
a known ABI. If no known ABI is found the architecture string itself is
returned.
added more paths to pull by default when device.get_properties is
invoked during run initialization. Also moved the LinuxDevice
implementation into BaseLinuxDevice, so that AndroidDevice tires to pull
the same files (on top of the Android-specific stuff).