Xcode project: added missing TTAudioObjectBase.h/.cpp files
Foundation Xcode project: organizing the TTObject-related files into a group of their own.
TTClipper extension: whitespace
TTClipper extension: fix for description property on the HighBound attribute actually setting the description for the LowBound, discovered during prep for LSU talk.
updates for TTValue usage to quiet some deprecation warnings
TTAudioObject: maxNumChannels renamed to follow our conventions, i.e. mMaxNumChannels, so that we can use our set of macros with it unmodified
TTAttribute: new property available to attributes that defines a default value.  If a an attribute is set with no value then the default value property will be used.  By default, the default is 0.  Resolves some problems where crashes or thrown exceptions would occur after we changed the TTValue to be based on std::vector, because we can no longer call methods on an 'empty' value.
TTAudioObject: the MaxNumChannels attribute now has a default value property set to 1 channel.  Thus resolving problems when instantiating audio objects without providing any arguments, as I was attempting to do during a talk at LSU this past week when I discovered this failure...
TTClass: when an exception is thrown trying to create a class, make a console post.