Implements paging and adding counters

refactored counterviewcontroller into counterchildviewcontroller
added new counterviewcontroller class
set up paging protocol methods
added a reference to a counterviewcontroller in childcounterviewcontroller
added an initialization method to counterchildviewcontroller that sets the parent controller
added a + button and blank addnewcounter method, linked it all up in xib
added incrementnumberofviews method to counterviewcontroller