evolve: make sure div resolution don't replace the initial author (issue6113) Before this patch, divergence resolution logic taking the current user who is running the resolution command as the author of commit that will be created after merging the two divergent csets. This patch make sure that we preserve the initial author. Changes in test file reflect the fixed behaviour.

evolve: add test which demonstrate issue6113 This patch introducing a new test file which contains the test for issue6113 which is `test-evolve-content-divergent-distributed.t`. This test file is supposed to contain tests for distributed workflows. Next patch will fix the bug.