redone backend handling and config parsing

tickLeisteServer.cabal

@@ -1,6 +1,6 @@
 cabal-version: 1.12
 
--- This file has been generated from package.yaml by hpack version 0.34.2.
+-- This file has been generated from package.yaml by hpack version 0.34.4.
 --
 -- see: https://github.com/sol/hpack
 
@@ -46,6 +46,7 @@ flag https
 executable tickLeisteServer
   main-is: Main.hs
   other-modules:
+      Backend.Backend
       Backend.CGI
       Backend.FastCGI
       Backend.Http
@@ -65,6 +66,7 @@ executable tickLeisteServer
     , bytestring
     , containers
     , http-types
+    , optparse-applicative
     , text
     , tickLeiste
     , tickLeiste-aeson
@@ -113,6 +115,7 @@ test-suite tickLeisteServer-test
     , bytestring
     , containers
     , http-types
+    , optparse-applicative
     , text
     , tickLeiste
     , tickLeiste-aeson