eXpress tool added.
Merge branch 'master' of https://github.com/chipster/chipster.git

Conflicts:
	src/main/modules/ngs/ngs-module.xml
Corrected the -a option in Bowtie2
New eXpress tool for quantifying gene expression at transcript level.
Merge branch 'master' of https://github.com/chipster/chipster.git