Nextflow

- Fixed an issue while checking an - empty - process exit file
- Fixed a race condition while resuming cached tasks

- Fixed file close leaks
- Fixed DirectoryStream close leaks
- Enhanced process executor, supporting multiple executors in the same pipeline

- Changed caching hash function to murmur3_128 to avoid cache collision
- Fixed issue on process termination when resuming pipeline execution

- Major executors refactoring
- Featuring new single-thread tasks scheduler
- New enhanced DSL syntax with extended semantic
- Switched file handling to new NIO.2 file system
- Introducing support for DNAnexus cloud platform
- Removed unnecessary library dependencies
- Slim self-contained executable package

- Extending semantic for method File.copyTo(source,target) so that when 'target' argument
is a directory, it copies the 'source' file to that folder, with the same name as the original file.
- Bug: Fixed a ClassCastEx exception when the 'bin' folder is added to the PATH
- Bug: Fixed an issue that raised an error "error=26 Text file busy" on some platforms (CentOS)

- Added optional parameters to 'chunkLines' and 'chunkFasta' methods
- Added '-lib' command line parameter specify external libraries (.jar files) or extension scripts
- Folder 'lib' in the launch directory is added by as default libraries path
- Added 'tempFile()' and 'tempDir()' methods to BaseScript class
- The 'bin' directory in the script folder is added to the task PATH environment by default
- Upgraded to Groovy 2.1.6
- Upgraded to Slf4j 1.7.5
- Upgraded to Logback 1.0.13