Ticket #55: savannah: tab completion vs. spaces and escaping

* Split big functions.
* Add unit tests

Signed-off-by: Slava Zanko <slavazanko@gmail.com>
Extend QUICK_INPUT and QUICK_LABELED_INPUT macroses for getting completion flags via parameters instead of using hardcoded value

Signed-off-by: Slava Zanko <slavazanko@gmail.com>
Concretize the usega of autocompliting in different input fields.

Signed-off-by: Slava Zanko <slavazanko@gmail.com>