Added two tests that check whether calling the RunInTransaction method in the Database class commits or rollbacks the transaction depending on the delegate return value.
Merge remote-tracking branch 'upstream/master' into TMRunInTransactionTests
Wrote a test that simulates two concurrent transactions that become nested and then successfully proves that two transactions can affect each other by 'forcing' a failed transaction to be committed.
Added the ignore attribute to the test that verifies issues with concurrent/nested transactions.
Merge pull request #343 from tiagomargalho/TMRunInTransactionTests

Added tests that check if RunInTransaction works as expected