Nextflow

- New command line option '-log' to specify the application log file
- New command line options '-task.xxx' to task default parameters (overriding the ones in the configuration file)
- Fixed a bug which was preventing the caching mechanism to work properly
- Fixed synchronization issue caused by a miss-used CountDownLatch, replaced with a Phaser
- Fixed a bug by which cached tasks didn't print out any result when 'echo' was set
- Fixed a bug in the timezone handling in the build timestamp

- Added command line parameter 'echo' to enable default tasks output
- Fixed an issue on merge task, when it doesn't collect any data the execution is skipped

- Decoupled the processing policy by the execution strategy classes
- Normalised script level arguments so that a blank char may be used in place of the equals char
- Added a new configuration option named 'clusterOptions' where specify grid native configuration parameters
- Added a new configuration option named 'scratch' which enable/disable usage of scratch temporary folder when using cluster executors
- Enhanced implementation of LSF executor

- Added 'lefTrim' and 'rightTrim' extension methods to String class
- The task script interprets correctly the 'shebang' header declaration
- The task save the command environment to a separated file, in order to simply task reproducibility and debugging

- Adding '-pool-size' cli option and config parameter to define size of executor threads
- Removed SGE output file
- Initial SLURM support

- Adding 'test' feature