Vertex memory allocation uses malloc and realloc without checking the
result. Throw exceptions that can be caught in the DoRepaint() method
in EDA_DRAW_PANEL_GAL when malloc and realloc return a null pointer.
Previous implementation uploaded only vertices with indices less
or equal to the number of stored vertices, which is invalid when
the container become fragmented.
Fixes: lp:1712887
* https://bugs.launchpad.net/kicad/+bug/1712887
Wayne Stambaugh
Roberto Fernandez Bautista
Maciej Suminski