makefile generation -- addressing some compiler warnings on the mac
TTElement: adding a != operator, which is required for upcoming use of != in TTValue.
TTValue: fix for uninitialized member when using most of the constructors.
TTValue: defining an == operator instead of relying the default so that we can debug comparisons -- might want to ifdef this out for performance in release builds.
value cache now initializes values via constructors instead of using an initialization function.  this allows us to also define these constants as const to catch errors such as over-writing their values accidentally.
TTDictionary: fix for problems with keys not being consistently stored/recalled using their raw pointer.
fix for bad usage of kTTValNONE that could result in memory corruption