When repository contains a Slack type hook,
it changes original payload content.

This patch fixes it by using a local object to store
newly created Slack payload instead of assigning
back to the same variable.

- Update locales

path.Dir can't handle Windows case, must use filepath.Dir

- Change tooltip size from mini to tiny in profile page

This makes the code more strict since you can't assign or compare
values of different types without proper cast.

We set the default value for the non-NULL field NumFollowing of the User
model to 0, which stops an error when the ORM tries to sync.

- User profile un/follow
- List user's followers/following

(untested)