set buildtime vars, cleanup comments

/cc @alexclark

bin/compile

 #!/usr/bin/env bash
 
-# This script serves as the
-# [**Python Buildpack**](https://github.com/heroku/heroku-buildpack-python)
-# compiler.
-#
-# A [buildpack](http://devcenter.heroku.com/articles/buildpacks) is an
-# adapter between a Python application and Heroku's runtime.
-#
-# You can intreract with the Heroku API directly with [heroku.py](https://github.com/heroku/heroku.py/).
-#
-# See also: [Release history](/changelog.html), [Detection](/detect.html).
-#
-# ## Usage
-# Compiling an app into a slug is simple:
+# Usage:
 #
 #     $ bin/compile <build-dir> <cache-dir>
 
 
-# ## Assumptions
-#
-# This buildpack makes the following assumptions:
-#
-# - The desired Python VM is available on the base system.
-# - Library dependencies are available on the base system.
-# - Django applications should not require any platform-specific configuration.
-
-# <hr />
-
-# ## Context
-
 # Fail fast and fail hard.
 set -eo pipefail
 
@@ -79,9 +55,9 @@ BUILD_DIR=$APP_DIR
 # Prepend proper path buildpack use.
 export PATH=$BUILD_DIR/.heroku/python/bin:$PATH
 export PYTHONUNBUFFERED=1
-
-# ## Build Time
-#
+export LANG=en_US.UTF-8
+export LIBRARY_PATH=/app/.heroku/vendor/lib
+export LD_LIBRARY_PATH=/app/.heroku/vendor/lib
 
 # Switch to the repo's context.
 cd $BUILD_DIR