Removed monadic and dyadic operators from the AST

This is the first part of a change, suggested in #64, to remove operators in favour of functions (which will also allow user-defined operators).

The ticket suggested removed operators after the parser, but the way it's working out, it is fine to just never represent as anything other than function calls.

All the knock-on changes will be recorded in later patches.

data/AST.hs

@@ -257,12 +257,8 @@ data Variable =
 
 -- | An expression.
 data Expression =
-  -- | A monadic (unary) operator.
-  Monadic Meta MonadicOp Expression
-  -- | A dyadic (binary) operator.
-  | Dyadic Meta DyadicOp Expression Expression
   -- | The most positive value of a given type.
-  | MostPos Meta Type
+    MostPos Meta Type
   -- | The most negative value of a given type.
   | MostNeg Meta Type
   -- | The size of the outermost dimension of an array type (see 'SizeExpr').
@@ -304,27 +300,6 @@ data ExpressionList =
   | AllocChannelBundle Meta Name
   deriving (Show, Eq, Typeable, Data)
 
--- | A monadic (unary) operator.
--- Nothing to do with Haskell monads.
-data MonadicOp =
-  MonadicSubtr
-  | MonadicMinus
-  | MonadicBitNot
-  | MonadicNot
-  deriving (Show, Eq, Typeable, Data)
-
--- | A dyadic (binary) operator.
-data DyadicOp =
-  Add | Subtr | Mul | Div | Rem
-  | Plus | Minus | Times
-  | BitAnd | BitOr | BitXor
-  | LeftShift | RightShift
-  | And | Or
-  | Eq | NotEq | Less | More | LessEq | MoreEq
-  | After
-  | Concat
-  deriving (Show, Eq, Typeable, Data)
-
 -- | An item in an input.
 data InputItem =
   -- | A counted input.