Updated changelog, release 1.8.1

Update IDE version to 1.8.0

Updated Wifi101 firmware updater to ver 0.8.3

Releasing 1.6.12

Workaround for MacOSX gatekeeper (OSX 10.10.4)

Reapply d6c5344 until avrdude 6.3
is fixed.

Releasing IDE 1.6.10

Merge branch 'master' of github.com:arduino/Arduino

update arduino-builder to 1.3.14

Updated revision log

Releasing IDE 1.6.6