Minimal RPC protocol

[Helveg]

I think a minimal new RCP protocol for what small part of the API #21 provides could look like this:

• create_cell(roots): Create a cell from a list of root Section descriptors (with children). Returns the ID/name?
• remove_cell(id)

We'd just need to settle on an AoS or SoA (#22) description of Sections.

Would you like to keep using names (which might lead to more of #15) or switch to something ID based, with names being GUI flavor on top? The neuron RPC could still map its section names to the IDs that the new RPC returns.

[Helveg]

I couldn't help myself and in my original description added in nice-to-haves in the core spec. I removed them and list them here for later reference:

• create_morphology(name, roots): Client asking the server to store this set of root Sections under a certain name, so that cells can be templated from it.
  • This should help when n_cells >>> n_morphologies
• create_population(template, positions, rotations): Go over the given iterables and for each set of items (template, position, rotation) a Cell is created (, grouped in a CellGroup.) Returns the ID/name?
  • The template can either be 1 set of roots used for the entire population, or a list of pre-stored morphology names/ids
• remove_population(id)/remove_cells(list_of_ids)
• remove_morphology(name): Remove the template if your use for it is gone (eg all cells created)