python: Remove duplicate code
PythonInstalled: Don't require superenv

* The python do ... end block does no longer
  require 'superenv' but saves and restores
  the ENV by using ENV.to_hash and `ensure`.
  This should resolve some build problems
  with formulae using `env :std`!
* `python_helper` is now in a module `Python`.
* Imporoved some comments in python_dependency.rb
python: --HEAD option added and more robust builds

* Added a head for python 2.7
* Using `build.with?` instead of `build.include? 'with...'`
* More robust temporary linking of opt/python/bin during
  install and cleanup (with ensure).
Hotfix: Revert Python module
depends_on :python don't set any LDFLAGS

Setting LDFLAGS to `-F HOMEBREW_PREFIX/opt/python/Frameworks`
breaks at least the scipy build. Perhaps others, too.
linkapps: replace #max_by with #max

Enumerable#max_by didn't exist in 1.8.6, so linkapps failed on Leopard.
InspIRCd 2.0.13

Closes #20304.

Signed-off-by: Misty De Meo <mistydemeo@gmail.com>
spidermonkey: remove use of autoconf

Closes #20296.
Use ivar accessors
cleanup: use String#[] instead of "captures.first rescue nil"
LuaJIT 2.0.2

LuaJIT 2.0.2 is the new stable (released 2013-06-03)

Closes #20305.

Signed-off-by: Misty De Meo <mistydemeo@gmail.com>
bottles: use String#[] instead of "captures.first rescue nil"
git: use opt_prefix for pcre
git: detect presence of perl's ExtUtils::MakeMaker