[mapper] implemented manyHasMany relationship limit [closes #3]
[repository] added new findBy and getBy methods to interface (BC Break!) [closes #26]
[mapper] manyHasMany optimized UNION to UNION ALL
[tests] fixed pgsql tests data reseting db state
[mapper] fixed oneHasMany limiting relationship [closes #25]
[testsHelper] added addMethod support
Revert "[tests] fixed weird nette/tester method run order"

This reverts commit ca87cca74f72da5f73aed2434f122ff9c271f365.
Revert "[tests] fixed more nette/tester test order weirdness"

This reverts commit 1c3c9fbdc7f1cc63894809bd32d15d1ccc97082a.