Apply drogon's patch

2014-05-20 : changed to pin mode to support softPwm.
(http://git.drogon.net/?p=wiringPi;a=commit;h=05e2f67e7f43d83195fff108bc
d952e7afe917ce)
2014-06-24 : Updates for the Raspnerry Pi Compute Module - changes to
the gpio program
(http://git.drogon.net/?p=wiringPi;a=commit;h=6fba403b2f749ae0ea64019037
fc692f2de1483d)
2014-06-24 : Bumped version to 2.15
(http://git.drogon.net/?p=wiringPi;a=commit;h=7cbb8865c8dc6675618a17492a
1175c278d38685)
suppress compilation warnings

Cast from pointer to integer of different size.
lines : 1727, 1733, 1739, 1745, 1752
Merge branch 'incoming'