close issue #26
Alternative dry run, dumping the pipeline is bash scripts inside the current directory
basic checkpointing with a simple touch file, possible advanced implmentation using md2sum on command line
jump to 0.5.12
shrink errore message for each command.
use --spooler to choose the depoly methods
do not care about lock files
log each command in a step; set pbs queue
log gin steps is buggy due to bash isolation
Merge pull request #27 from helios/master

merging @helios pull request: close issue #26