Added [Ignore] to some tests which weren't working. Thanks Shay for
feedback. See Pull Request 18.

A lot of tests were not working and based on Shay's feedback
https://github.com/franciscojunior/Npgsql2/pull/18 those [Ignore] flags
were added in order to get all tests green. Those failing tests were
giving us trouble to identify regressions.
Add support for new error fields added in PostgreSQL 9.3

This makes the new error information available in the Exception class
which allows the calling code to, for example see which constraint would
be violated by the request.
See PostgreSQL commit message for more details on what extra information
is available and when. This commit only captures the extra information
when it's there.

http://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=991f3e5ab3f8196d18d5b313c81a5f744f3baaea
Adds new test for newly added exception fields

This code is untested as I've not yet worked out how to run the test
suit.
The constant values in the Assert.AreEqual() calls may need tweaked.
The prime purpose of the patch is to test that the fields are properly
being populated. There is no need to also test things like foreign key
violation as its testing the same code in Npgsql.
Fixed wrong assumptions about new Exception Tests

After reading the source code of PostgreSQL9.3, it seem that only
certain errors relating to domain types will populate the DataTypeName
field. This commit adds 2 new tests. 1 to test for the column name, as
the previous uniqueviolation did not show the column name which unique
constraint was violated. Perhaps this has to do with the fact that
unique constraints can exist for >1 column. Test 2 checks the
datatypename after a domain's NOT NULL constraint is violated.

I've not yet run the tests. Though I did compare after setting psql \set
VERBOSITY verbose
Renamed newly added file and added copyright

Renamed Exception.cs to ExceptionTests.cs and added copyright notice to
the top of the file
Fix missing [Test] clauses from newly added test

Also for the unique violation test I've added some asserts to ensure
that the data type and column name are empty. These are not populated
for unique violations, originally I removed the tests but on after
thought it's probably better to ensure that they're empty strings.
Tidy up of new test functions

Renamed the 3 new test functions to give them more suitable names. Also
added comment to explain why a domain is created to test the
DataTypeName field. I would have guessed that we could see this
populated by violating a NOT NULL constraint on a table's column, but
this does not seem to be the case.