Changes for compatibility with ghc-7.10-rc2

2 modules: Name clashes caused by Applicative-Monad change in Prelude
2 modules: Ambiguities caused by Foldable/Traversable in Prelude
2 modules: Backwards incompatible changes in time-1.5 for defaultTimeLocale
9 modules: {-# LANGUAGE FlexibleContexts #-} (because GHC checks inferred types
           now, in addition to explicitly given type signatures)

Also silenced warnings about tab characters in source files.

src/compiler/GF/Compile/SubExOpt.hs

@@ -21,6 +21,7 @@
 -- 
 -----------------------------------------------------------------------------
 
+{-# LANGUAGE FlexibleContexts #-}
 module GF.Compile.SubExOpt (subexpModule,unsubexpModule) where 
 
 import GF.Grammar.Grammar