Fix some compilation errors on Mac

Builds/MacOSX/open-ephys.xcodeproj/project.pbxproj

Builds/VisualStudio2012/open-ephys.vcxproj

Builds/VisualStudio2012/open-ephys.vcxproj.filters

Builds/VisualStudio2013/open-ephys.vcxproj

Builds/VisualStudio2013/open-ephys.vcxproj.filters

Source/Plugins/ArduinoOutput/Makefile

Source/Plugins/BasicSpikeDisplay/Makefile

Source/Plugins/CAR/Makefile

Source/Plugins/ChannelMappingNode/Makefile

Source/Plugins/FilterNode/Makefile

Source/Plugins/KWIKFormat/Makefile

Source/Plugins/NetworkEvents/Makefile

Source/Plugins/PhaseDetector/Makefile

Source/Plugins/PulsePalOutput/Makefile

Source/Plugins/RecordControl/Makefile

Source/Plugins/Rectifier/Makefile

Source/Plugins/SerialInput/Makefile

open-ephys.jucer