add BCF support

git-svn-id: svn+ssh://svn.internal.sanger.ac.uk/repos/svn/pathsoft/artemis/trunk@15174 ee4ac58c-ac51-4696-9907-e4b3aa274f04

ChangeLog

 Version 12.+
+	Add support for reading in indexed BCF (Binary VCF) files.
+	
 	Memory optimisation of codon caching, reducing the memory footprint.
 	
 	It is now possible to add BAM / VCF files from the command line using the