merge from upstream

… for vertices (they check correctly now).

Paq.sh now automatically outputs to nuklear.h.

keharriso's Prevent clicking more than one (overlapping) button per frame.
However, this has a couple of other changes that should fix dropdowns from intefering as well.

…nto fix_click

- Sets click to 0 every start of frame
- Input was still down for that frame, so it triggered the next event
Now it waits for your button to go back up before resetting the clicked variable, so as long as your mouse is down, only one item is clicked.

…checkbox!

With README changes that show off more features and the updated style. Slightly modified.

…nto fix_radio_buttons

…nto fix_radio_buttons

…nto fix_click

…nto fix_radio_buttons

…uklear into latest

…mension of the window (if it is resizable). All old functionality will remain the same (it used to return 1 instead of a pointer, but if(nk_begin) will remain the same, since it checks for 0).

Removed nk_add_window_titled as it wasn't implemented and nk_add_window provides the same functionaltiy.

…ed with an if(!0) doError(), strict C++17 won't compile due to an if that should be constexpr.

Replaced const char** in combobox with const char * const *, since const std::vector<String> should be supported.
Added error messages to a few NK_ASSERT(0), so if it crashes it doesn't just abort without any info.

…into feature_subpixel_api

Fixed C++17 strict compilation.

…iangle next to it that can't expand.

Now using + and - instead of right and down triangle; I find -+ more minimalistic.