Rough sketch of formats doc.
Update formats.md
Merge pull request #205 from ambiata/topic/formats

Rough sketch of formats doc.
Fix spelling in formats.md
fixed the scoverage compilation
Remove unused Namespaces.partitionSizes
Extract separate Namespaces.namespaceSizesSingle
Introduced allNamespaceSizes to Namespaces
Add LongIntWritable for rename
Added ability to rename features