Differentiate Integer type from Double type (which was originally named Number) to make it possible to correctly store a 64bit integer on 32bit systems.

Differentiate Integer type from Double type (which was originally named Number), make it possible to correctly store a 64bit integer on 32bit
systems.

Note: this commit will stop programs that use the original **jsonxx** lib
from compiling. it is required to change the enum *Number* to either
*Integer* or *Double* accordingly.