v0.019

    Modifications to Genoverse track show/hide controls
    Use log4perl configuration from WGE_LOG4PERL_CONFIG
removed some noisy debug statements
added filtered crispr track
added user inputs for crispr off-target filtering
colour crisprs grey if their off-targets have not been computed
added colour key to genoverse page
refactored genoverse track code into separate file
javascript tidy up
crispr pairs now filtered by off-target profile
added spacer length filter and controls
existing crispr filters are now applied without full page reload. crispr color is restored if off-target filters are relaxed
off-target filters in draggable menu
some user interface improvements
bugfix - crispr pairs within design now coloured grey
track rename and user interface improvements
no filtering at all on bookmarked crispr and pair tracks
layout changed and reset button added for spacer filter
minor ui fixes
changed order of js scripts to avoid button method name clash
exon length fix. trailing whitespace removed from code