Change of integer type

[xavitator]

It is a proposition of @FauconFan :

There is some language where char, short, int and long primitive variables are not defined to have respectively 8, 16, 32 and 64 bits (such as in C for int). So we can introduce :

• int8
• int16
• int32
• int64

to replace this language restriction.

And add 'u' before them to have an unsigned value.

[FauconFan]

Refer #19

Otherwise, it's a good idea for me