BPackageManager: Add mandatory constructor parameters

Require the installation interface and the user interaction handle to
be passed to the constructor. Formerly, derived classes set them
manually in their constructors. This makes using the class without
having to subclass it possible.

headers/private/package/manager/PackageManager.h

@@ -57,7 +57,11 @@ public:
 
 public:
 								BPackageManager(
-									BPackageInstallationLocation location);
+									BPackageInstallationLocation location,
+									InstallationInterface*
+										installationInterface,
+									UserInteractionHandler*
+										userInteractionHandler);
 	virtual						~BPackageManager();
 
 			void				Init(uint32 flags);