add ability to categorize test data for functional tests (fixes #3421, BP from #3404)

(cherry picked from commit a3beff99b303105c04cbf40dd3918ed3f1828504)
fix method declaration error in action classes (fixes #3419, BP from #3405)

(cherry picked from commit 0e5c3ff1759e6a35048b3eb4367dd38057c53a44)
ignore E_STRICT error for Net_UserAgent_Mobile::factory() (fixes #3417, BP from #3406)

(cherry picked from commit 5749159540e18f2af0e3bc5373f72a3ddeefe5c8)
remove opCommunityTopicPlugin dependency in testcases (fixes #3432, BP from #3423)

(cherry picked from commit 03554f57d9dc2ec7ca3543280210c675ec06046e)
fix `Array to string conversion' error in opI18N (fixes #3433, BP from #3424)

(cherry picked from commit 015897d36b9272059c74a27e74c6d2639e9c3243)
remove useless include in designActionsTest.php (fixes #3434, BP from #3425)

(cherry picked from commit 74943a28fb7cb3da51dd3bae47283708a266540f)
remove useless tests in pc_backend (fixes #3435, BP from #3426)

(cherry picked from commit 66829df2516fd50053d2c94a7425d0fc7041b952)
remove skeleton tests for mobile_frontend and mobile_mail_frontend (fixes #3438, BP from #3431)

(cherry picked from commit 5542d6174689fe6951093e37f493f8aaa5c892f4)
remove skeleton tests for pc_frontend (fixes #3438, BP from #3431)

(cherry picked from commit 52010fe24dd57de0c5265689f96986677452c5e7)
fix fallback error when activity_templates.yml doesn't exist (fixes #3439, BP from #2773)

(cherry picked from commit 6864bf36d7df3b7acb25d6fc9a5c45de519140a9)
fixed "IsTrim" option (fixes #3448, BP from #2104)

(cherry picked from commit 9a9d99dd054733b5a296a0885bb4ff605f7d06a9)
make IsRequired and IsTrim optional in opFormItemGenerator (fixes #3437, BP from #3428)

(cherry picked from commit 0962d48b8fbfa2da9be0d65764a569bf9ccfd1e7)