Added old-locale flag.

This will ease transition to time 1.5.  However, currently we can't
build with time 1.5 because of dependencies.

pandoc.cabal

@@ -211,6 +211,10 @@ Flag network-uri
   Description:   Get Network.URI from the network-uri package
   Default:       True
 
+Flag old-locale
+  Description:   Use old-locale and time < 1.5
+  Default:       True
+
 Library
   Build-Depends: base >= 4.2 && <5,
                  syb >= 0.1 && < 0.5,
@@ -225,8 +229,6 @@ Library
                  bytestring >= 0.9 && < 0.11,
                  text >= 0.11 && < 1.3,
                  zip-archive >= 0.2.3.4 && < 0.3,
-                 old-locale >= 1 && < 1.1,
-                 time >= 1.2 && < 1.5,
                  HTTP >= 4000.0.5 && < 4000.3,
                  texmath >= 0.8 && < 0.9,
                  xml >= 1.3.12 && < 1.4,
@@ -252,6 +254,11 @@ Library
                  old-time,
                  deepseq-generics >= 0.1 && < 0.2,
                  JuicyPixels >= 3.1.6.1 && < 3.3
+  if flag(old-locale)
+     Build-Depends: old-locale >= 1 && < 1.1,
+                    time >= 1.2 && < 1.5
+  else
+     Build-Depends: time >= 1.5 && < 1.6
   if flag(network-uri)
      Build-Depends: network-uri >= 2.6 && < 2.7, network >= 2.6
   else
@@ -399,7 +406,7 @@ Executable make-pandoc-man-pages
                  directory >= 1 && < 1.3,
                  filepath >= 1.1 && < 1.4,
                  old-time >= 1.0 && < 1.2,
-                 time >= 1.2 && < 1.5
+                 time >= 1.2 && < 1.6
   Default-Language: Haskell98
   if flag(make-pandoc-man-pages)
     Buildable:   True