[fs][ext2] read only ext2 fs support
[warnings] fix a couple of dangling warnings in some little-used libs
[include] add stdbool.h according to C99
[include] remove stdbool.h and stddef.h, which should come from the compiler

-move def of ssize_t to sys/types.h, which may not be entirely correct
[include] rearrange some locations of defines to better match C99

Conflicts:
	include/app.h
	include/compiler.h
[include][sys][types.h] switch ssize_t back to unsigned long

This is really the proper type for all the arches lk cares about.
Also include stddef.h for size_t.
[include][sys] add shorthand integer types

u8/u16/u32/u64 and s8/s16/s32/s64 for those who prefer minimum verbosity
fix compile after stdbool update
[lib][ext4] add lwext4 ext4 library