Added [IssueLink] for semantic markup of tests
(cherry picked from commit 7cb67b24fd1abd16a8a31f706c7b4b11090f5a07)

Conflicts:

	tests/TestUtil.cs
Fix rollback to savepoint when timeout is set

Fixes #363
(cherry picked from commit aa913dd28c1c78f4b2bd8af241c8d9a955f8d9c6)

Conflicts:

	Npgsql/Npgsql/NpgsqlTransaction.cs
	Npgsql/NpgsqlConnector.cs