Fix bed2interval from 0-base bed to 1-base interval

From the Picard javadoc:
http://picard.sourceforge.net/javadoc/net/sf/picard/util/IntervalList.html

Interval files are 1-based whereas BED files are 0-based
Merge pull request #93 from kevyin/patch-1

Fix bed2interval from 0-base bed to 1-base interval