Massive use of fixed integer types

All integer types (with the exception of char) have been changed
to equivalent fixed types taken from C99 spec and wrapped around new
typedefs. This has been made as a huge effort to control all integer
sizes at runtime, so their portability becomes guaranteed.

- long long becomes q_int64_t
- int and long int becomes q_int32_t
- short and signed short becomes q_int16_t
- byte is now a wrapper of q_uint8_t
- unsigned int becomes now q_uint32_t
- unsigned short becomes now q_uint16_t
- unsigned char becomes now q_uint8_t