gummiboot/builder: fix timeout setting when unset

The gummiboot-builder.py script is expecting the @timeout@ metavar to be
substituted for either an empty string (in the case where a user has
left the timeout unset) or the actual value set in the system
configuration.

However, the config.boot.loader.gummiboot.timeout option defaults to
'null', and due to the way pkgs.substituteAll works, the substitution
for '@timeout@' is _never_ set to the empty string.  This causes the
builder script to put a bogus line into /boot/loader/loader.conf:

   timeout @timeout@

Fix this by explicitly setting 'timeout' to the empty string when it's
unset in the system configuration.

Signed-off-by: Josh Cartwright <joshc@eso.teric.us>
Update oraclejdk-7 patch version from 65 to 67
sudo: add sendmailPath option (defaults to /var/setuid-wrappers/sendmail)

It currently seems impossible to make sudo send emails. No matter how much
debugging I enable, sudo continues to be silent about sendmail. I tried setting
"Defaults mailerpath=/var/setuid-wrappers/sendmail" but that too was completely
ignored (except for logging that the variable mailerpath exists with the value
I assigned to it...).

This enables sendmail support and sets a default value that works on NixOS.
Removed mysql dependency as it does not pick up the header files on Linux, even when specified explicitly in the config params.
haskell-MFlow: update to version 0.4.5.9
haskell-crypto-random: update to version 0.0.8
haskell-digestive-functors-heist: update to version 0.8.6.0
haskell-entropy: update to version 0.3.3
haskell-hplayground: update to version 0.1.0.4
haskell-monad-journal: update to version 0.2.3.2
haskell-network-uri: update to version 2.6.0.1
haskell-purescript: update to version 0.5.5
haskell-rest-gen: update to version 0.15
haskell-rest-happstack: update to version 0.2.10.2
haskell-retry: update to version 0.5.1
haskell-setlocale: update to version 1.0.0
haskell-x509: update to version 1.4.12
haskell-network: update to version 2.6.0.2
haskell-ghc-mod: update to version 5.0.1.2
haskell-tls: update to version 1.2.9 (and drop obsolete tls-extra)