Well, here's the first pass on regression

Well, here's the first pass on regression
tests for the Foreign Key support in 7.0 which
was made against a CVS copy from this
afternoon.

This modifies
 src/test/regress/sql/run_check.tests
 src/test/regress/sql/alter_table.sql
 src/test/regress/expected/alter_table.out
 src/test/regress/sql/foreign_key.sql
 src/test/regress/expected/foreign_key.out

sszabo@bigpanda.co