Added preferences to select instruction paper size and orientation
Updated data model to support pictureWidthInPins AssemblyType and addedVolumeInCubicPins for DetailType and also pictureSizeInitial and pictureSizePrepared for both of them; Implemented calculation of the details/assemblies images relative sizes based on estimation of their volume;
Implemented calculation of the step numbers in build instruction (some more tests are needed which is blocked by UI bug on iOS 7/8); Refactoring: separated calculateInstalledAssembliesGroupsForAssemblyType:intoArray:andDictionary: method from AssembliesAndDetailsViewController to be reused in AssemblyValidator;