Renamed WGI_RESPONSE_BUFFER as WGI_RESPONSE to avoid confusion
Removed EWF_HEADER and removed related caller from WGI implementation,
now this is only part of WSF library
Added wgi_version, wgi_implementation and wgi_connector to the WGI_REQUEST interface
to give more information to the user
Added back WGI_CONNECTOR to WGI specification, mainly because of `{WGI_REQUEST}.wgi_connector'
simplified WGI_CONNECTOR to contain for now only `name' and `version'
if the implementation of connector inherit from WGI_CONNECTOR (recommended)
this might gives more access to the user using a reverse assignment for specific needs
(but this usage is not recommended due to portability issue on other connector)
Removed useless connector.ecf since now EWF/WGI library provides the helper classes
