Partitura Magica Code2

refactored UpdateCommand to use new abilities of
Rect class.
Rect class can perform update operations with respect to
MinSize and a "outer rectangle"
tests pass

introduced own immutable Rect class
all tests pass

removed unused assembly refs
before adding own Rect class

fine tuned BoxFinder, bug fix regarding Partpattern

AutoFillCommand finally works

Refactored Splitters inside Box.cs
new class SplitterList

migrated to nunit 2.5.2

Before changing to NUnit

BoxFinder reliably finds note lines now,
still missing: make box tall enough to include all above and below the system
Removed unnecessary references to assemblies

Make Boxfinder relative to image size