Upgrade trac to the v 1.2

[Alex Samorukov]

Trac current is now v 1.2. To keep server secure and up to date i would recommend to migrate to it from the 1.2 version. Steps to do:

1. Try to upgrade locally, from the backup.
2. Check if custom functionality (plugins) is working. List of the plugins could be found in WIKI. Some of them do have small local modifications.
3. If upgrade works well - put server into maintenance mode and repeat steps on prod. Prepare roll back plan if everything goes wrong
4. Notify users and test all basic functionality