[de]allocate all decomp vars in serial region, not just gathered/scattered ones
names_in_region -> vars_in_region (filter out subprogram items)
in Nonlabel_Do_Stmt#translate, add 'use sms__decomp' if needed
update TODO
strip subscript list from variable-name string in SMS_Exchange#translate
add dir$ to sentinels, allow sentinels in declaration constructs
write envfile to directory containing input source file (not sure if good idea)