removing redundant conditions in if else 
removing redundant conditions in if else 

1) When an if condition leads to a break I cannot see a reason as to why it will be satisfied in another if condition latter .
 2) Also to get chrom id easily and in a faster way, we could use an array with indexes as keys 
3) RtreeIndex could simply return indexOffset+48 as it is always a fixed size header for the R-tree.
dpryan79/libBigWig,dpryan79/libBigWig