provide backup/restore of full pilosa data

[tgruben]

Description

The current pilosa backup command requires an index,frame, and view names as input. In order to perform a complete backup, every view must be manually requested. This could be greatly simplified if the command handled all the details and produced a nice compressed file that could be restored at a later time.

Success criteria (What criteria will consider this ticket closeable?)

pilosa backup --uri HOST:IP --outputDirectory /mnt/backup/ #this will produce a file /mnt/backup/backup20171011.pak pilosa restore --uri HOST:ip backup20171011.pak

[jaffee]

perhaps not identical, but related: https://github.com/pilosa/pilosa/issues/725

[jaffee]

This import view work (unmerged) may end up being relevant to backup/restore strategy: https://github.com/pilosa/pilosa/pull/733

[jaffee]

this also may be relevant: https://github.com/pilosa/pilosa/pull/743