Add delay after pin export
Fix analog read

The pins where not initialize properly
Check if the analog overlay is already enable
Only export GPIO pin if not exported yet
_ can't be use as return value :)
Seek pin file back to the beginning before each read
Change driver detection for ubuntu

If the hostname is change driver detection breaks
currently only change it for ubuntu since I don't have angstrom BBB to
find a better way to auto detect the driver
Merge branch 'develop' of github.com:jarias/hwio