Merge pull request #557 from nomis52/master

Fix the Windows build.
Added vendor string for Open DMX clone from KWMATIK
Merge pull request #560 from tuffnerdstuff/master

Added vendor string for Open DMX clone from KWMATIK
Add support for the Open Pixel Control protocol.

This is just missing the final code for the OPC client.
Update the plugin doc now we allow more libusb debug states
Finish off the rest of the OPC code.
Fix lint and license warnings.
Get the usbdmx plugin working on older versions of libusb
Todo
Fix the build
Fix errors found by the latest cpplint
Add the client test, fix a bug.
Fix a memory leak and build warning.
Fix Simon's comment
Merge pull request #561 from peternewman/libusb

Get the usbdmx plugin working with older versions of libusb
Merge branch 'master' of github.com:OpenLightingProject/ola into opc
Add the GPIO plugin.

I need to do some timing tests.
Merge branch 'master' of github.com:OpenLightingProject/ola into gpio
Merge branch 'opc' of github.com:nomis52/ola into gpio

Conflicts:
	common/protocol/Ola.proto
Add the missing Makefile