Sam: add getter and setter methods for mapq
Added non_ref_het() returning true only if it is a het() and none of the alleles is the reference (key == 0)
Fixes #211
Merge pull request #221 from nsubtil/sam-mapq

Sam: add accessor method for mapq
Merge pull request #223 from broadinstitute/ks_non_ref_het_211

Added non_ref_het()
Sam: add insert_size member function

fixes #224
Merge pull request #225 from broadinstitute/mc_insert_size

Sam: add insert_size member function
Sam: rename next => mate