maybe instead of a model we'll just use a Text/qstring
reserve the chatText qstring, to prevent costly reallocs
maybe a readonly textedit is best, as that gives us selections

and it doesn't take on system theming
beginnings of a chat dialog..
use glm::distance for comparison only between float vecs

ivec's cnanot be compared as such..we convert player->lastLoadedChunk
to such types because having that as a non-int doesn't make sense.
Change the way the OpenGL debug callback is registered.

Previously debug.h declared the callback as a public function, and
client.cpp registered it. Now debug.h declares a function to register
the callback, and client.cpp just calls that. This lets me avoid
exposing the callback in the header at all.
Merge branch 'qtquick-attempt' into winbuild

* qtquick-attempt:
  Change the way the OpenGL debug callback is registered.
  Use glm::distance for comparison only between float vecs.
  Beginnings of a chat dialog.
  Maybe a readonly textedit is best, as that gives us selections.
  Reserve the chatText qstring, to prevent costly reallocs.
  Maybe instead of a model we'll just use a Text/qstring.