* refactor(storage): move type ByTagKey to the only package that uses it
* refactor(tsdb): use types in tsdb/cursors
* refactor(tsdb): remove unused type SeriesIDElems
* refactor(tsdb): inline only use of tsdb.ReadAllSeriesIDIterator
* refactor(tsdb): move series file to its own package
* refactor(storage): remove platform->influxdb aliases
I did this with a dumb editor macro, so some comments changed too.
Also rename root package from platform to influxdb.
In interest of minimizing risk, anyone importing the root package has
now aliased it to "platform" so that no changes beyond imports were
necessary in those files.
Lastly, replace the old platform module to local path /dev/null so that
nobody can accidentally reintroduce a platform dependency while
migrating platform code to influxdb.
Jonathan A. Sternberg
Jacob Marble
Mark Rushakoff
Edd Robinson