renamed ENVIRONMENT_NAMES into META_NAMES
better usage of READABLE_STRING_GENERAL, and other strings
abstract RESPONSE_BUFFER in implementation of EWSGI
for the implementation, inheriting from deferred specification (more to come later)
Re-adapt the Spec-compliant solution (instead of Lib-compliant solution).
Thus no more 100% deferred interface.
Rename EWSGI_RESPONSE into EWSGI_RESPONSE_BUFFER
Added in extra/response-as-result/ an copy/paste from the implementation of Paul's proposal (not up to date with Paul's spec). But this is mainly for information and tests.
Removed part of the ewsgi/specification interfaces ... to be able to test EWSGI compliant library against the pure specification (experimental).
Renamed most of the GW_... into EWSGI_...
