Added runReduceF :: (a -> ReduceM b) -> TCM (a -> b)
Builtin bindings for extended lambda

Not yet supported by quote/unquote
[ refactor ] move code for quoting clauses to quotingKit
Update Common.Reflect with extended lambda constructor
Quote extended and absurd lambdas
Changed type of AGDATERMEXTLAM to take a list of arguments
Fixed comment
Quoting functions need to run in the reduce monad

to make sure they can access updated signatures
Fixed problem quoting absurd patterns
Test case for quoting extended lambda
Unquoting extended lambdas.

The way unquoting works is a little awkward at the moment. We
unquote to internal syntax, and then we convert the result back
to abstract syntax for type checking. To get extended lambdas
working I had to add them to the internal syntax. They shouldn't
leak out of the unquote -> reify -> type check chain though.
Release notes for extended lambda reflection.
Merge branch 'quote-ext-lam'