Percentage usage of disk space of an Oracle XE 11g database

From @Dani3lSun (#38)

Percentage usage of disk space of an Oracle XE 11g database
https://gist.github.com/Dani3lSun/c2e0f8bb249ec2ae7bd2

Create a new packaged called `oos_util_dba` but this package won't be part of the default install as it requires DBA privileges. Will require modifications to the install scripts to exclude the DBA package.
