* Update to envDefaults: if environmental varialbe ONOS_CELL is set,
the load it, so its variables can be used by other scripts
* Modifications inside tools/dev/bash_profile:
- Update the setting of JAVA_HOME so it works for Ubuntu with
OpenJDK-1.7
- Removed "." from being added to the PATH, because it is a security hole
* Add ONOS-specific directories to the executable PATH in the envDefaults file
* Fix a typo inside "onos-show-cell": don't show OC0, because it is not used