Adapt to work with GHC 6.12

- Adapted the package to work with GHC 6.12
- Plugins that depend on the old base3 are currently
  not correctly loaded as the plugin loaded misses
  the dependence on syb (leading to unresolved symbols)
- Cleaned up most of the testsuite (there are still
  some outstanding failures, of which only one
  demonstrates a bug in the plugins library as far
  as I can see — see previous bullet point)
- Cleaned out a little cruft (but more could be done)

testsuite/dynload/should_fail_2/Plugin.in

@@ -9,7 +9,7 @@
 module Plugin where
 
 import API
-import AltData.Typeable
+import Data.Typeable
 import GHC.Base
 
 v :: Int

testsuite/dynload/should_fail_2/Plugin.stub

@@ -3,7 +3,7 @@
 module Plugin ( resource_dyn )  where
 
 import API
-import AltData.Dynamic
+import Data.Dynamic
 
 resource = plugin
 

testsuite/dynload/should_fail_2/api/API.hs

@@ -2,7 +2,7 @@
 
 module API where
 
-import AltData.Typeable
+import Data.Typeable
 import GHC.Base
 
 data Interface = Interface {