Sync changelogs with 2.0.

[ci skip]

Cabal/changelog

 -*-change-log-*-
 
-2.0.0.0 (current development version)
+2.2.0.0 (current development version)
+	* TODO
+
+2.0.0.0 Ryan Thomas <ryan@ryant.org> May 2017
+	* The 2.0 migration guide gives advice on adapting Custom setup
+	scripts to backwards-incompatible changes in this release:
+	https://github.com/haskell/cabal/wiki/2.0-migration-guide
 	* Add CURRENT_PACKAGE_VERSION to cabal_macros.h (#4319)
 	* Dropped support for versions of GHC earlier than 6.12 (#3111).
 	* GHC compatibility window for the Cabal library has been extended
@@ -109,6 +115,11 @@
 	* Support for "foreign libraries" (#2540), which are Haskell
 	  libraries intended to be used by foreign languages like C.
 	  Foreign libraries only work with GHC 7.8 and later.
+	* Added a technical preview version of integrated doctest support (#4480).
+	* Added a new 'scope' field to the executable stanza. Executables
+	with 'scope: private' get installed into $libexecsubdir. Private
+	executables are those that are expected to be run by other
+	programs rather than users, like ghc-mod helpers. (#3461)
 
 1.24.0.0 Ryan Thomas <ryan@ryant.org> March 2016
 	* Support GHC 8.

cabal-install/changelog

@@ -4,7 +4,7 @@
 	* 'cabal update' supporst '--index-state' which can be used to
 	roll back the index to an earlier state.
 
-2.0.0.0 (current development version)
+2.0.0.0 Ryan Thomas <ryan@ryant.org> May 2017
 	* Removed the '--root-cmd' parameter of the 'install' command
 	(#3356).
 	* Deprecated 'cabal install --global' (#3356).
@@ -48,6 +48,8 @@
 	only apply to top-level dependencies. They don't constrain setup or
 	build-tool dependencies. The new syntax --constraint="any.bar == 1.0"
 	constrains all uses of bar.
+	* Added a technical preview version of the 'cabal doctest' command
+	(#4480).
 
 1.24.0.0 Ryan Thomas <ryan@ryant.org> March 2016
 	* If there are multiple remote repos, 'cabal update' now updates