Add metadata value for 'all' hazard for fixing #952.
Fix weak warning.
Update metadata for mmi depth.
Add converter dictionary.
Add coverter to old keywords and unittest.
Remove unit_mmi_depth.
Code standard.
Merge with develop.
Merge pull request #963 from ismailsunni/fix_953

Fix 953
Tested under ubuntu 12.04
Fix IF Volcano Building for preventing using the same target field with one of the hazard attributes.
Merge pull request #970 from akbargumbira/revisit_IF

Fix IF Volcano Building
Pylint
Merge pull request #971 from ismailsunni/fix_pylint

Pylint