Process for removing __rte_experimental

[Shreyansh Jain <shreyansh.jain@nxp.com>]

While reading through [1], I couldn't understand if __rte_experimental 
and EXPERIMENTAL tag removed from code and map file, respectively, are 
categorized under ABI breakage or not. Thus, whether deprecation for 
them should be sent or not in a release cycle for removal in subsequent 
release.

Logically, EXPERIMENTAL APIs are not part of stable APIs/ABIs and hence 
they don't really break an ABI. Thus, deprecation for them doesn't make 
sense. (or, as Luca noted on IRC, removing experimental is like 
de-deprecation :) )

On IRC, Luca pointed out that in one of the Tech Board meeting minutes 
[2], this was recorded but that too has slight ambiguity to it.

Any thoughts on this? Or, was this documented somewhere other than [1]?

[1] http://dpdk.org/doc/guides/contributing/versioning.html
[2] https://dpdk.org/ml/archives/dev/2017-October/079961.html (Section 2-b)