Add Show Scroll Bar

[arandomdev]

This allows the user to set if the vertical scroll bar is visible. Changes seem to take affect on timeline refreshes, and force quitting the app. This should also address #119.

Lastly, I wrapped the "Fix login keychain in non-JB (IPA)" hooks in a preprocessor block to make it easier to enable and disable it.

[BandarHL]

Thanks for "Fix login keychain in non-JB (IPA)" that was a lifesaver I swear 😂😂

[imassig]

Hi can you add option for timeline tweats count something like this? Thanks