Added a flag to disable scrolling after section closing + weak block reference

[natalia-osa]

When user closed a section, the tableView did scroll this way, that closed section was on the top of the screen. This change adds a flag, which by default behaves the same way as the old code, but if set to NO - disables this jumping.

[natalia-osa]

Seems it would be useful to make Travis scripts to update the whole configuration of the cocoapods: http://stackoverflow.com/questions/35563329/cocoapods-frameworks-sh-error-no-such-file.