embedded documents following depth level
embedded documents following depth level

embedded_fields may point on a field that come from another embedded
document. For example, ['a.b.c', 'a.b', 'a']

The strategy is to sort out the different embedded_fields depending on
their number of '.'. This way, the ones with the greatest depth level
come last.

Combined with https://github.com/RedTurtle/eve-sqlalchemy/pull/47 it's
now possible to do include multi-level embedded resource with Eve-SQLAlchemy.

eduardomb/eve,mcreenan/eve,bcrochet/eve,kalbasit/eve,EasonYi/eve,stratosgear/eve,matthieuprat/eve,elpoisterio/eve,julianhille/eve,pjs7678/eve,hustlzp/eve,yanyanqin/eve,mugurrus/eve,sebest/eve,kidaa/eve