Implement new auto-process 'info' command

[pjbriggs]

Implements a new info command within auto_process.py, as a lightweight alternative to using the metadata and params commands to get information about the current analysis directory.

Information to include:

• Run ID
• Bases mask
• Flow cell mode
• Run configuration

(The PR includes updates to the setup command internals, to acquire and store a new run_configuration metadata item which describes the reads and numbers of bases determined from the RunInfo.xml file of the sequencing run (e.g. R1:101bp, I1:8bp, I2:8bp, R2:101bp). The run configuration is generated by a new function get_run_config, in the bcl2fastq/utils module.)