#1545 Add C99 and later keywords to C lexer

[dosfan01]

Add C99 and later keywords like restrict to the C lexer. Also add the common types from stdint.h - int8_t, int16_t, int32_t, int64_t, intmax_t, intptr_t, uint8_t, uint16_t, uint32_t, uint64_t, uintmax_t, uintptr_t

[Neil Hodgson]

That would be useful if anyone wants to contribute a change.