fixes error while accessing constants.py variables from twokr.py.
changed python runtime for src/ files.
added hadoop-started field to conf/2kr.conf.
updating src/constants.py: now DB_ROWS_MIN is a function of another
constant (DB_MAX_RATIO) and hadoop and iaee each have their own waiting
constant.
src/iaee.py fixed to consider machines that have hda* as partition
names.
many changes in src/twokr.py.
updating to.do.
many changes in src/run-2kr.py.