paired reads must belong to the same readset
First step to fileData cleanup

- inline the headerSections field
- remove the header object, because neither sorting_order nor bam version is applicable in this format
- remove fileUri for the same reason
add context (GA4GH links, team mission)
paired reads must belong to the same readGROUP
Merge remote-tracking branch 'upstream/master' into filedata-move

Conflicts:
	src/main/resources/avro/ga4gh.avdl
Merge pull request #21 from cassiedoll/filedata-move

First step to fileData cleanup
Merge pull request #15 from dglazer/mated-reads

paired reads must belong to the same readgroup
Merge pull request #31 from dglazer/readme-mission

add context (GA4GH links, team mission)