rtorrent: update to version 0.9.3

This version is dubbed "unstable" and apparently it lacks the man page that
used to come with earlier releases. :-(

We need the latest version, though, because of the recent update to libtorrent.
dropbear: update from 2013.60 to 2013.62
add meta.repositories.git to several packages
haskellPackages.extensibleEffects: New expression
haskellPackages.IntervalMap: New expression
haskellPackages.exPool: New expression
haskellPackages.haskelldb: New expression
Merge pull request #1347 from ocharles/extensible-effects

haskellPackages.extensibleEffects: New expression
Merge pull request #1350 from ocharles/haskelldb

haskellPackages.haskelldb: New expression
Merge pull request #1349 from ocharles/ex-pool

haskellPackages.exPool: New expression
Merge pull request #1348 from ocharles/intervalmap

haskellPackages.IntervalMap: New expression
gmime: update from 2.6.15 to 2.6.19
calibre: upgrade 1.13.0 -> 1.14.0

Signed-off-by: Moritz Ulrich <moritz@tarn-vedra.de>
cabal: add support for the enableStaticLibrary flag to enable/disable building of static libraries

Disabling static libraries is supported only in GHC 7.7 or later.
haskell: Propagate cabal dependencies to user env

Before this commit, if a haskell library X depends on Y, and X was added to
systemPackages, only X would be available in the user environment. Y
would not be avialable, which causes X to be broken. This commit solves
the issue by setting propagatedUserEnvPkgs to all packages X depends
on when X is a library.
haskell-errorcall-eq-instance: add version 0.1.0
haskell-case-insensitive: update to version 1.1.0.2
haskell-http-client-*: new packages
haskell-parsers: update to version 0.10.1.2
haskell-text: update to version 1.0.0.0