Fixes #72

Save disk sizes in KB in the disk model. Update the retrieval code for disks
and shares to consistantly save and return numbers in KB.
Change the size input scale to KB by default.
Modify to make default size scale to KB.
Merge pull request #76 from Mchakravartula/issue#59_humanize_size

Issue#59 humanize size
Merge pull request #74 from schakrava/issue#72_disk_sizes

Fixes #72