Add test for loading a bed file from FTP

Currently failing, this is a real bug

IGV-1910
Use updated tribble which properly handles registerHelperClass

Tribble built on this developers machine (Mac OSX 10.7.5, ant 1.8.4) using:
 ant -Dant.build.javac.target="1.6" -Dant.build.javac.source="1.6" -Dsam-version="r1414" clean tribble-jar

IGV-1910