* Timers now are Application thread safe
* Timers now have consistent API independend of Application (no more c style timers)
* Timers can have either: callback or override onTimer() method - this
way we can create more complicated timers or just use existing ones
* gui::Timer added via adapter class GuiTimer to decouple sys::Timer
with gui::Timer
* Fixed race in wrapper
* Updated docs
* fixed using std and cpp_freertos and DataReceivedHandler hidden in Application.hpp
* elements which possibly depended on this depend now on `visibility` of element added
* changed everywhere returns on addWidget
* checked layouts (vertical, horizontal, pagedbox, gridlayout)
* tryAddWidget was redundant to addWidget, with Rect fixes and log it's not needed
* With changes in BoundingBox simplified axis use in BoxLayout
* Add widget moves elements to it's place, resize is not thought through and for now is removed