expr object

[ylevtov]

@mhroth Just noticed that Chris' compressor patch has an expr object in there. Could we either add that into the XCode project (the license is only a problem if we aim to put it in the App Store, right?), or could you tell me how to perform a tanh operation on a number using only vanilla objects?

[mhroth]

@ylevtov I'll have to double check the expr object. Otherwise I could make a tanh external.