refactored run_sstable2json and run_json2sstable to use file handles rather than paths
refactored run_sstable2json and run_json2sstable to use file handles rather than paths

pombredanne/ccm,umitunal/ccm,bcantoni/ccm,mikefero/ccm,EnigmaCurry/ccm,kishkaru/ccm,pcmanus/ccm,tolbertam/ccm,mambocab/ccm,spodkowinski/ccm,unusedPhD/ccm,pcmanus/ccm,pcmanus/ccm,jeffjirsa/ccm,jorgebay/ccm,mike-tr-adamson/ccm,mikefero/ccm,josh-mckenzie/ccm,thobbs/ccm,mike-tr-adamson/ccm,thobbs/ccm,bcantoni/ccm,mike-tr-adamson/ccm,tolbertam/ccm,aboudreault/ccm,AtwooTM/ccm,slivne/ccm