Revert "Fix buildbot.test.unit.test_changes_p4poller tests"

Instead tuning tests for modified input, I'll try not to modify input.

This reverts commit 9507d33fc078d8d4a3d50895c56b52db7ba39144.
Revert replacing tabs with spaces
Use \t instead tabs to make pep8 happy
Merge branch 'revert_p4_change_log_tabs' of git://github.com/vrutsky/buildbot into nine