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/PGFtoPython.hs

@@ -6,6 +6,7 @@
 -- exports a GF grammar into a Python module
 -----------------------------------------------------------------------------
 
+{-# LANGUAGE FlexibleContexts #-}
 module GF.Compile.PGFtoPython (pgf2python) where
 
 import PGF(showCId)