Added new properties

[sebromero]

Added the following three properties:
@Property(assign, nonatomic) BOOL longPressToEraseEnabled;
@Property(nonatomic,readonly) NSUInteger vertexCount;
@Property(weak, nonatomic)id signatureViewDelegate;

This allows to get notified once the signature has changed. Also the vertex count can be read so you can e.g. decide whether a signature is valid / contains enough vertices. Also the long press to erase function can be disabled.

[sebromero]

Any update on this?

[kusiak]

good stuff, thanks for that :)