Add 'lens' Haskell dependency

.. that will be used in WConfd
Signed-off-by: Petr Pudlak <pudlak@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

INSTALL

@@ -62,18 +62,6 @@ packages, except for RBD, DRBD and Xen::
                     python-pyparsing python-simplejson python-bitarray \
                     python-pyinotify python-pycurl python-ipaddr socat fping
 
-For older distributions (eg. Debian  Squeeze) the package names are
-different.::
-
-  $ apt-get install lvm2 ssh bridge-utils iproute iputils-arping make \
-                    ndisc6 python python-pyopenssl openssl \
-                    python-pyparsing python-simplejson python-bitarray \
-                    python-pyinotify python-pycurl python-ipaddr socat fping
-
-If bitarray is missing it can be installed from easy-install::
-
-  $ easy_install bitarray
-
 Note that the previous instructions don't install optional packages.
 To install the optional package, run the following line.::
 
@@ -133,7 +121,7 @@ Starting with Ganeti 2.7, the Haskell GHC compiler and a few base
 libraries are required in order to build Ganeti (but not to run and
 deploy Ganeti on production machines). More specifically:
 
-- `GHC <http://www.haskell.org/ghc/>`_ version 6.12 or higher
+- `GHC <http://www.haskell.org/ghc/>`_ version 7 or higher
 - or even better, `The Haskell Platform
   <http://hackage.haskell.org/platform/>`_ which gives you a simple way
   to bootstrap Haskell
@@ -150,7 +138,7 @@ deploy Ganeti on production machines). More specifically:
 - `curl <http://hackage.haskell.org/package/curl>`_, tested with
   versions 1.3.4 and above
 - `hslogger <http://software.complete.org/hslogger>`_, version 1.1 and
-  above (note that Debian Squeeze only has version 1.0.9)
+  above.
 - `hinotify <http://hackage.haskell.org/package/hinotify>`_, tested with
   version 0.3.2
 - `Crypto <http://hackage.haskell.org/package/Crypto>`_, tested with
@@ -163,6 +151,8 @@ deploy Ganeti on production machines). More specifically:
   above
 - `lifted-base <http://hackage.haskell.org/package/lifted-base>`_,
   version 0.1.1 and above.
+- `lens <http://hackage.haskell.org/package/lens>`_,
+  version 3.0 and above.
 
 Some of these are also available as package in Debian/Ubuntu::
 
@@ -176,12 +166,6 @@ Some of these are also available as package in Debian/Ubuntu::
                     libghc-attoparsec-dev libghc-vector-dev \
                     libghc6-zlib-dev
 
-Or in older versions of these distributions (using GHC 6.x)::
-
-  $ apt-get install ghc6 libghc6-json-dev libghc6-network-dev \
-                    libghc6-parallel-dev libghc6-deepseq-dev \
-                    libghc6-curl-dev
-
 In Fedora, some of them are available via packages as well::
 
   $ yum install ghc ghc-json-devel ghc-network-devel \
@@ -207,7 +191,7 @@ ones not available in your distribution packages) via ``cabal``::
 
   $ cabal install json network parallel utf8-string curl hslogger \
                   Crypto text hinotify==0.3.2 regex-pcre \
-                  attoparsec vector base64-bytestring
+                  attoparsec vector base64-bytestring lens
 
 Haskell optional features
 ~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -220,8 +204,7 @@ The extra dependency for these is:
 - `snap-server` <http://hackage.haskell.org/package/snap-server>`_, version
   0.8.1 and above.
 
-This library is available in Debian Wheezy (but not in Squeeze), so you
-can use either apt::
+This library is available in Debian Wheezy, so you can use either apt::
 
   $ apt-get install libghc-snap-server-dev
 
@@ -231,15 +214,6 @@ or ``cabal``::
 
 to install it.
 
-In case you still use ghc-6.12, note that ``cabal`` would automatically try to
-install newer versions of some of the libraries snap-server depends on, that
-cannot be compiled with ghc-6.12, so you have to install snap-server on its
-own, explicitly forcing the installation of compatible versions::
-
-  $ cabal install MonadCatchIO-transformers==0.2.2.0 mtl==2.0.1.0 \
-                  hashable==1.1.2.0 case-insensitive==0.3 parsec==3.0.1 \
-                  network==2.3 snap-server==0.8.1
-
 .. _cabal-note:
 .. note::
   If one of the cabal packages fails to install due to unfulfilled

NEWS

@@ -93,6 +93,8 @@ For Haskell:
 
 - ``lifted-base`` library (http://hackage.haskell.org/package/lifted-base)
 
+- ``lens`` library (http://hackage.haskell.org/package/lens)
+
 
 Version 2.10.0
 --------------

configure.ac

@@ -607,6 +607,7 @@ AC_GHC_PKG_REQUIRE(text)
 AC_GHC_PKG_REQUIRE(hinotify)
 AC_GHC_PKG_REQUIRE(Crypto)
 AC_GHC_PKG_REQUIRE(lifted-base)
+AC_GHC_PKG_REQUIRE(lens)
 
 # extra modules for confd functionality; also needed for tests
 HS_NODEV=