Refactor help handling

Refactor help handling so that common help strings are inherited from base classes. This significantly reduces duplication of help strings within the code.
Replace "pragma mark" directive with comments

Replace Xcode-specific "pragma mark" directives with comments since "pragma mark" is meaningless outside of Xcode
Add 'add_weak_classifier' to ml.adaboost
Add ml.zerox zero crossings counter

Add zero crossings counter and base classes for other feature extraction objects
Delete erroneous plist file
General tidy up

- Removed unneccessary comments
- Made help strings static members and moved to bottom of files
- Removed empty destructors
Add zerox Pd help instead of Max for testing
Delete erroneous zerox Max help
Fix missing dot notation

A number of objects didn't have the capability to be added using dot notation "ml.*". This is fixed in this commit.
Fix paths to Pd binary for testing purposes

This controls what is run when the target is "Run" in Xcode. It now expects Pd-extended.app to be in /Applications and runs the correct binary, passing in the relevant Pd help file if there is one.
Add error checking to feature extraction map()
Refactor loop counter with iterator
Version bump
Update package generation script

Update package generation script with feature extraction sources
Generate package files for extraction objects