sam_test.go: rewrite TestReadSeqByIndex() using io.SectionReader
moving test sequence data under same directory and corresponding code changes
supporting bam indexing and samtools view functionalities in API
Merge branch 'master' of github.com:MG-RAST/Shock
Merge pull request #36 from wtangiit/master

support bam format indexing (bai), filtering (bam->sam), and "samtools view" APIs
support provenance info in node: parent and children fields and updating APIs
provide APIs for updating data type and file format (node.Type & node.File.Format)
fixes empty query null error
attribute update support
make provenance info more generic
disable checking for relation type vocabulary
Merge pull request #38 from wtangiit/master

provenance info and some new APIs for updating data info
merged changes
Merge pull request #41 from jaredwilkening/master

attribute update support
fixed merge issue
Merge pull request #42 from jaredwilkening/master

fixed merge issue
minor fix
Db access clean up
provide querynode API
fill info in  Node.Indexes when creating index