Mostly portable implementations of extensions for me; __thread, bool, inttypes.h, variadic macros, flexible array members etc. But declaring variables closer to

Mostly portable implementations of extensions for me; __thread, bool, inttypes.h, variadic macros, flexible array members etc. But declaring variables closer to the point of use is nice, as is struct initializers, compound literals and single line comments. Compared to the rest, C99 contains a lot of useful improvements.