Use a sed() function for unbuffered output.

In `bin/steps/collectstatic` the unbuffered output in `indent` is subverted
by calling `sed` first:

```shell
python $MANAGE_FILE collectstatic --noinput  2>&1 | sed '/^Copying/d;/^$/d;/^ /d' | indent
```

This commit fixes this by making `sed` itself unbuffered rather than
putting that logic in the `indent` function.
Use consistent syntax for declaring functions in utils
Stop calling find for simple operations. Just use extglob.

Additionally use `cp -a` consistently rather than alternating between
`cp -a` and `cp -r`, and don't fail compile if the glob doesn't expand to
anything.
dotglob FTW. Doesn't expand . or .. but be explicit just in case.
Update Readme.md
Merge pull request #120 from agriffis/sed-func

Use a sed() function for unbuffered output.
Merge branch 'stop-finding' of git://github.com/agriffis/heroku-buildpack-python into develop
bob-builder start
readme stub
improved collectstatic experience
handhold for collectstatic
no !
Merge branch 'master' into builds
builds for python
v0.0.5
deploy instructions
Add missing Makefile
Merge pull request #132 from dulaccc/fix-tests

Add missing Makefile
Make builds work when BUILD_DIR=/app

When building with either 'git push' or Anvil, BUILD_DIR is set to a
temporary directory (not /app). However, because the prebuilt Python
interpreter has a prefix of /app/.heroku/python baked into it, the
contents of BUILD_DIR need to be temporarily swapped into /app for the
rest of the buildpack to work.

This temporary swapping breaks other buildpack-compatible tools that
set BUILD_DIR=/app. So the fix is straightforward---skip the swapping
in this case.

Also alias bpwatch to a no-op when REQUEST_ID is not set, since this
indicates we're running outside the Heroku environment.