Add httpserver to contrib

.. see http://stefanfrings.de/qtwebapp/index-en.html

.. this is a lightweight web server to allow GC to
   provide webservices.

.. we will be providing web services on localhost to
   enable R integration.

.. we will use web services to standardise the
   interface to provide something we can use in R
   but also anything else at a later date.

.. gcconfig.pri contains $$HTPATH that points to
   the location of the code, if it is not set then
   the web server is not compiled in.

httpserver/httpserver.pri

@@ -0,0 +1,33 @@
+INCLUDEPATH += $$PWD
+DEPENDPATH += $$PWD
+
+QT += network
+
+# Enable very detailed debug messages when compiling the debug version
+CONFIG(debug, debug|release) {
+    DEFINES += SUPERVERBOSE
+}
+
+HEADERS += $$PWD/httpglobal.h \
+           $$PWD/httplistener.h \
+           $$PWD/httpconnectionhandler.h \
+           $$PWD/httpconnectionhandlerpool.h \
+           $$PWD/httprequest.h \
+           $$PWD/httpresponse.h \
+           $$PWD/httpcookie.h \
+           $$PWD/httprequesthandler.h \
+           $$PWD/httpsession.h \
+           $$PWD/httpsessionstore.h \
+           $$PWD/staticfilecontroller.h
+
+SOURCES += $$PWD/httpglobal.cpp \
+           $$PWD/httplistener.cpp \
+           $$PWD/httpconnectionhandler.cpp \
+           $$PWD/httpconnectionhandlerpool.cpp \
+           $$PWD/httprequest.cpp \
+           $$PWD/httpresponse.cpp \
+           $$PWD/httpcookie.cpp \
+           $$PWD/httprequesthandler.cpp \
+           $$PWD/httpsession.cpp \
+           $$PWD/httpsessionstore.cpp \
+           $$PWD/staticfilecontroller.cpp