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.
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