Simplified EWSGI interfaces

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

library/server/ewsgi/connectors/cgi/cgi-safe.ecf

@@ -10,7 +10,6 @@
 		<option warning="true" full_class_checking="true" is_attached_by_default="true" void_safety="all">
 		</option>
 		<library name="base" location="$ISE_LIBRARY\library\base\base-safe.ecf"/>
-		<library name="connector" location="..\connector-safe.ecf" readonly="false"/>		
 		<library name="ewsgi" location="..\..\ewsgi-safe.ecf" readonly="false"/>
 		<library name="http" location="..\..\..\..\protocol\http\http-safe.ecf"/>
 		<cluster name="src" location=".\src\" recursive="true"/>