[PL/pgSQL] %TYPE and array declaration - second patch

Hi

Pavel Stehule reviewed my first patch and pointed many
issues - thanks! This patch resolves three problems:

1. The main issue - variables with copied types (%TYPE
and %ROWTYPE attributes) can be declared as arrays.
Grammar has been extended to match new syntax.

2. It's possible to copy type from function argument of
composite type[1].

3. Enabling copying types from wider range of objects,
data type resolution takes into account more cases.
For example it wasn't possible to declare variable
of row type, and then copy type from field of such
variable (something like: declare x table%ROWTYPE;
y x.field%TYPE).

Patch includes new test cases and few words in documentation.

best regards
Wojciech Muła

[1] http://stackoverflow.com/questions/7634704/declare-variable-of-composite-type-in-postgresql-using-type