Add window subclass to handle drag and drop

The window subscribes to file drag type operations and declares
a DragDropDelegate protocol to its delegate to handle the actual
drag operation by forwarding the `performDragOperation:` call.
Implement open documents when dragging files
Merge pull request #9 from lkraider/window-dragdrop-open-file

Drag and drop into window to open files
Use signed ints for NSTag, 32 bit compatibility

MainMenu.xib fails to compile with a 32 bit ibtool, because of:
	IBXMLDecoder: The value (2483028224) for key (NSTag) is too large to
	fit into a 32 bit integer.
This also breaks HexFiend on 32 bit systems when compiled with a 64 bit
ibtool:
	*** Terminating app due to uncaught exception 'NSRangeException',
	reason: '*** -[NSKeyedUnarchiver decodeInt32ForKey:]: value
	(2483028224) for key (NSTag) too large to fit in 32-bit integer'

Replacing these integers with the decimal representations of their
signed interpretation fixes this problem. 64 bit systems will ignore the
leading 4 bytes when casing to NSStringEncoding turning
	0xFFFFFFFF94000100
into
	0x94000100.

See https://trac.macports.org/ticket/35244 where this was originally
reported and debugged.
Merge pull request #12 from neverpanic/master

Fix HexFiend on 32 bit systems
Added Compare Range of X and Y functionality.

- Added ability to diff on a range of the given files
- Updated [DiffDocument displayName] to incorporate range when present
- Moved Diff loading functionality out of AppDelegate and into
DiffDocument class via new static methods
Merge pull request #15 from soldoutactivist/master

Added ability to diff on a range of the given files
Change behavior of maximizeVisibilityOfContentsRange.
Better selection pulse behavior.
Reduce compiler warnings by adding appropriate casts.
Fix two more remaining warnings
enable+fix recommended warnings
Add UTF8 inspector
Add UTF8 inspector with fewer bugs o_O
fix analyzer bugs
fix schemas
array access bug in boyer moore
Merge branch 'master' into ARC

Conflicts:
	English.lproj/DiffComputationBanner.xib
	English.lproj/FindReplaceBanner.xib
	English.lproj/JumpToOffsetBanner.xib
	English.lproj/MoveSelectionByBanner.xib
	English.lproj/SaveBanner.xib
	HexFiend_2.xcodeproj/project.pbxproj
	HexFiend_2.xcodeproj/xcshareddata/xcschemes/Debug + UnitTests.xcscheme
	app/sources/AppDelegate.m
	app/sources/BaseDataDocument.m
	app/sources/DataInspectorRepresenter.m
	app/sources/HFDocumentOperationView.h
	app/sources/HFDocumentOperationView.m
	framework/sources/HFByteSlice.m
	framework/sources/HFByteSliceFileOperation.m
	framework/sources/HFPasteboardOwner.m
	framework/sources/HFSharedMemoryByteSlice.m
Fix remaining ARC bugs
Fixes for static analyzer warnings