Added timeout configuration for different volume create scenarios.

 * Updated blockstorage create_active_volume behavior method
   to use new create-method-specific timeout calculators and
   config iptions.
 * Fixed docstring discrepencies in behaviors and configs.
 * some pep8 fixes.

Change-Id: Ibcdd2e07cdbc86cc9c98136c72adc9912fde5551
Merge "Added timeout configuration for different volume create scenarios."