gca-select: small utility to extract field values
[core.Abstract] new select_field() function
gca-select: use new Abstract::select_field()
[core.Abstract] to_data() to access abstract as dict data
[core.Abstract] to_json() method to serialize data as json
[core.Session] to_json: general to json function
gca-client: Use Session.to_json()
[gca.util] new module with make_fields helper function
[core.Abstract] select_field() handle indices
gca-select: use make_fields() from util that can handle indices