Fixing typo, correcting to 'firehose'
adding new variable, TCGAFMP_SCRATCH, for path to large scratch space
adding TCGAFMP_DCC_REPOSITORIES, which will replace TCGAFMP_DCC_MIRROR and TCGAFMP_DCC_SNAPSHOT
replacing TCGAFMP_DCC_MIRROR with TCGAFMP_DCC_REPOSITORIES
replacing TCGAFMP_DCC_SNAPSHOT with TCGAFMP_DCC_REPOSITORIES
adding documentation and examples to required env variables
adding python utility module to check, verify, and provide a python dictionary with required environmental variables.