Bug fixes and optimizations
- Cleaned up DirectoryEntry to better handle original inode type (missing filetype descriptor)
- DirectoryEntry now properly identifies unknown files as such for original ext2 format
- Fixed bug in GroupDescriptor incorrectly numbering the block ranges due to assuming the block group start was always at block 1.
- Updated SuperBlock to properly read bit flags for EXT features.
- Added helper method to Utility for reading bit flags
- Added helper method to Utility for reading unsigned short values as Integers for compatibility

* Changes tested against ext2 and ext3 partitions at 100MB and 2GB partition sizes.