The complete structure definition has to be listed inside the declare
section of the structure variable for ecpg to be able to understand it.

sqlwarn[6] should be 'W' if the PRECISION or SCALE value specified in a SET
DESCRIPTOR statement will be ignored.

The error handling has to be improved by adding additional error-rules to
the parser.

it would be nice to be able to use :var[:index] or :var[<integer>] as
cvariable for an array var

What happens to the output variable during read if there was an
indicator-error? 

Add a semantic check level, e.g. check if a table really exists.

It would be nice if there was a alternative library using SPI functions
instead of libpq so we can write backend functions using ecpg.

remove space_or_nl and line_end from pgc.l

Missing features:
 - SQLSTATE
