Extended class comment
Added JavaDoc comments to IVirtualDiskEntry.
Added first tests for IVirtualDiskSpace

Only some very basic tests added. Still in work.
Started with JavaDoc comments for IVirtualDiskSpace

Not yet finished. Committed for easier merge.
Merge branch 'master' of https://github.com/groggi/eth-jcd

Conflicts:
	src/ch/se/inf/ethz/jcd/batman/vdisk/IVirtualDirectory.java
	src/ch/se/inf/ethz/jcd/batman/vdisk/IVirtualDiskEntry.java
	src/ch/se/inf/ethz/jcd/batman/vdisk/IVirtualDiskSpace.java