version: add 4th digit and helper macros

version: add 4th digit and helper macros

Applications can test versions, for compatibility, this way:
	#if RTE_VERSION >= RTE_VERSION_NUM(1,2,3,4)

RTE_VERSION was already defined for use with rte_config.
It is moved in rte_version.h and updated to current version number.

Note that the first tag having this helper is 1.2.3r2.
Releases r0 have not this patch.

Signed-off-by: Thomas Monjalon <thomas.monjalon@6wind.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>