Changes after code analysis

- Marked exceptions as serializable
- Moved native WinAPI-stuff to its own "NativeMethods"-class
- Made most parts of WinAPI-methods portable by using IntPtr-type
(except the ones containing bool)
- Changed relating code parts
- Added a "LocalizationHelper" for easier management of access strings
in the library
- Added IDisposable-interface to some classes where necessary
- Fixed several small memory leaks
- Checked for security leaks when setting SQL-commands (no leaks found
as all concerned types aren't strings and would detect corrupt data
immediately ;))
- Moved structures to own files
- Added "SystemInformation"-class for the statistics data
- Fixed a bug that let service-operation appear as access string when
adding file operations
- Changed event handlers of some events in the library from declared
delegates to "EventHandler<T>"-type with the relating EventArgs.