dual index refinements

ensure max length of "Index" used by MiSeq is the split dual indexs' size,
and use custom default_expected_tag in preference to Index{,2} when using
samplesheet as source of LIMS info
Merge remote-tracking branch 'wtsi-npg/devel' into dual_index

Conflicts:
	Changes
Merge pull request #175 from dkj/dual_index

Dual index - refinements
Change reference name and location
Merge pull request #192 from KateTaylor/reference_name_changes

Change reference name and location
wrapper object for the status and a script to write status to a file
use DateTime object to generate timestamp since it is known how to make it work consistently across hosts; update build file
pulled in status_object branch, updated status monitor