fix zlip, bzip2 and freetype building. other misc bugs

[ITotalJustice]

upgrades: zlib 1.2.11 -> 1.2.13 libpng 1.5.10 -> 1.5.30 bzip2 1.0.6 -> 1.0.8 freetype 2.10.4 -> 2.12.1

fixes:

• updated broke zlib url
• bzip2 was detecting system installed libs (harfbuzz and brotli) so i disabled them
• add back ntfs lib
• iso9660.c was checking if a bool was negative...
• iso9660.c was using strnicmp instead of strncasecmp

[ITotalJustice]

i found this repo has gcc 9.4 patches https://github.com/gligli/libxenon/commit/ecfea8fbdc605e0631deedbfb12daadaa3c82c4f, should i pull this commit into this pr?

[Swizzy]

Unfortunately, the iso9660 change shouldn't be done as it's not a true boolean (0 or 1) it's a integer really, for example it could return -8 which means there's no disc inserted as you can see here; https://github.com/Free60Project/libxenon/blob/master/libxenon/drivers/diskio/ata.c#L571 https://github.com/Free60Project/libxenon/blob/master/libxenon/drivers/diskio/disc_io.h#L37

Technically, this line here is wrong: https://github.com/Free60Project/libxenon/blob/master/libxenon/drivers/diskio/ata.c#L572 since it checks for non-0 as true when infact it should check if it's positive.

[ITotalJustice]

Hi, i likely won't have time to come back to this pr. Feel free to pick anything from it that's useful