consider pict compatible schema format

[eviltester]

Our column definitions are currently

column name
definition

And an enum would be

Enum1
list, of, values
Enum2
enum("list","of",values")

Support the Pict column format.

Column name: definition

e.g.

Enum1: list, of, values
Enum2: enum("list","of","values")

This should enable a more pict compatible format ad seems like a more 'DSL' style definition.

We still want to support the existing

column name
definition

two line format

But, if we scan and find a

column name: CSV list
column name: valid DSL command

then treat the line as the : separated PICT format