Make examples/nanovg-demo.lua a bit more idiomatic
Make examples/nanovg-demo.lua a bit more idiomatic

A couple of metatable tricks are used to be able to write:

  nvg.LineTo(vg, x, y)
  nvg.LineTo(vg, x+10, y+10)

instead of:

  nvgLineTo = nvg.nvgLineTo
  nvgLineTo(vg, x, y)
  nvgLineTo(vg, x+10, y+10)

The final result is much more idiomatic Lua. As a final exercise,
using method on a table is left for future improvements.

aperezdc/eris,aperezdc/lua-eol,aperezdc/lua-eol,aperezdc/eris