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 pull request #178 from srl147/devel

HiSeqX change to seq_instr_checker
Merge pull request #179 from srl147/devel

added HX (HiSeqX) to $INSTRUMENT_PATTERN
Merge pull request #180 from wtsi-npg/devel

pull request from wtsi devel to master to create release 77.4
Merge pull request #181 from srl147/devel

added new version value for HiSeqX RunInfo.xml
Merge pull request #182 from srl147/devel

added changes for release 77.5
Merge pull request #183 from wtsi-npg/devel

pull request from wtsi devel to master to create release 77.5
Merge pull request #184 from srl147/devel

HiSeqX changes
Merge pull request #185 from wtsi-npg/devel

pull from wtsi devel to master to create release 77.6
Merge pull request #186 from wtsi-npg/master

pull from wtsi master to devel
Merge pull request #187 from srl147/devel

HiSeqX changes
ensure samplesheet test works without WTSI filesystem present
Changes update; code formatting
remove deleted test data from MANIFEST
Merge branch 'devel' of github.com:wtsi-npg/npg_tracking into devel2

Conflicts:
	Changes
Merge pull request #190 from dkj/wtsi_free_samplesheet_test

WTSI free samplesheet test
Travis CI configuration and associated changes
attempt to patch intermittently failing test: retrieve time after it was updated
Merge pull request #191 from mgcam/travis_ci

Travis CI configuration and associated changes
Merge remote-tracking branch 'wtsi-npg/devel' into dual_index

Conflicts:
	Changes