Merge pull request #474 from hpcugent/v1.8.0.x

rel
Merge pull request #544 from hpcugent/develop

release EasyBuild v1.9.0
added samtools-0.1.19 and required patches
this depends on modified samtools.py easyblock
add easyconfig for SAMtools with ictce/5.5.0, clean up corresponding goolf easyconfig
add missing zlib easyconfig for ictce/5.5.0
Merge pull request #593 from boegel/samtools-0.1.19

add easyconfigs and patch for SAMtools 0.1.19