datatable upload: name collisions

The datatable table has an index on table name:

CREATE TABLE datatables_datatable
(
  id serial NOT NULL,
  title character varying(255) NOT NULL,
  table_name character varying(255) NOT NULL,
  tablespace character varying(255) NOT NULL,
  uploaded_file character varying(100) NOT NULL,
  create_table_sql text,
  CONSTRAINT datatables_datatable_pkey PRIMARY KEY (id),
  CONSTRAINT datatables_datatable_table_name_key UNIQUE (table_name)
)
WITH (
  OIDS=FALSE
);

Add code to handle name collissions

IQSS / geoconnect

datatable upload: name collisions #96