makefiles now build static libs in addition to dynamic libs on the mac
added comment in yaml parsing -- we appear to have a huge block of code that does nothing and should be axed.
added flag to makefiles to properly hide non-exported symbols
added missing preprocessor symbols definitions for Graph and AudioGraph libs so that they actually export their symbols.
TTAudioSignal: update use of TTValue methods.
Graph library: fix broken export macro on the Mac.