Simplification.
Updated ENet to 1.3.9.
nullptr.
Renamed headers to .hpp for syntax highlighting.
Cleaned up vertex pool allocation.
Updated GLM to 0.9.4.6.
Removed last use of Singleton.
Used C++11 deletion for non-copyable types.
Enabled image-less texture creation.
Added key modifiers.
Added TrueType typeface support.
Added utf8cpp 2.3.4.