WOFF fonts cause double free on exit

[nimble0]

Reproducing:

• Add a WOFF font, such as Xolonium, to Samples/assets
• Add { "Xolonium-Regular.woff", false }, to the font faces list in Shell.cpp
• Launch and close any sample

Looks like FreeType::ReleaseFace expects FT_Face->stream->base to hold a pointer to the data pointer that was passed in but in the case of WOFF fonts it doesn't.

[mikke89]

Thank you for the detailed report! The FT_Face->stream->base pointer must certainly have been a hack, I've restructured a bit and it should be fixed now, much safer. Let me know if there are any issues.