delete no use imports
Merge pull request #171 from scwf/deletenouseimports

delete no use imports
Merge pull request #169 from manugoyal/common-util-additions

Added methods to CommonUtils
how to run tests
Cleaned up and documented MasterInfo and related files

Major changes:
1. InodeFolder stores its children as Inodes rather than inode ids. This
simplifies many operations
2. Writing and loading filesystem images is modified accordingly to work
with the new InodeFolder structure
3. Cleanups and improvements to many of the core MasterInfo methods