removed waiting for pressing any key before exit

introduced the PackageFormatter and TestCaseHandler

extracted the parse, validate and pack to the separate classes

made Package smart to know about total weight and const

small optimization to remove unsatisfactory combination immidiately during generating

simplified Packer methods

implemented the simplest algorithm to pack

implemented outputing the package as the list of indexes

immplemented test case validation

implemented parse method for test cases

introduced domain objects: TestCase, Thing and Package

added base contracts

init commit