Merge pull request #2 from wtsi-npg/devel

merge changes from wtsi-npg
Merge pull request #177 from wtsi-npg/master

pull wtsi master (release 77.3) to wtsi devel
added list of top level directories for HiSeqX
Merge pull request #3 from wtsi-npg/devel

merge changes from wtsi-npg
Updated Changes file
Merge pull request #178 from srl147/devel

HiSeqX change to seq_instr_checker
added HX (HiSeqX) to $INSTRUMENT_PATTERN
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