[ Issue 1353 ] Test case (works on maint).
[ Issue 1350 ] Fixed haddocumentation and added tests of cluster functions.
Fixed typos
[ issue 1283 ] Added missing type signatures
[ issue 1283 ] Fixed

* Added -fwarn-missing-signatures to Agda.cabal
* Removed {-# OPTIONS -fwarn-missing-signatures #-} from the modules.
[ issue 1356 ] NameKind commands in agda.sty enforce no math spacing

Cherry-picked from https://github.com/agda/agda/commit/90c8becd4b8d22fabfa9c76deabc77f0402e0e53.
[ issue 1356 ] Added missing documentation
[ Issue 1357 ] Fixed by eta-expanding more projected variables.

Also those that are not only projected, but also applied to stuff (after
the projections).
[ bench ] Comparing std-lib bench for ghc-7.6 with ghc-7.8.