Update etl scripts and memorymb default value

Update etl scripts
    
Contains environments variables for etl scripts. Factorize some code and creates
symbolic links for hraven-core.jar and hraven-etl.jar if needed. Etl scripts now source this file.
    
Source hraven-etl-env.sh and add default values for costFile and rawFileSizeLimit.
Also calls jobFilePreProcessor.sh and jobFileProcessor.sh  with right arity and parameters from now.
    
source hraven-etl-env.sh
    
source hraven-etl-env.sh and add defaultRawFileSizeLimit to parameters
    
exports HBASE_CLASSPATH

Now set a default value for hadoop property mapreduce.map.memory.mb
which is not set in yarn conf by default