check path first

PipelineStorage.listdir short-circuit returning the first match only

check if path is exists

Fix whitespace in script tags, remove charset attribute for inline scripts

Before:
<script   type="text/javascript" ...
<script async  type="text/javascript" ...
<script  defer type="text/javascript" ...
<script async defer type="text/javascript" ...

After:
<script type="text/javascript" ...
<script async type="text/javascript" ...
<script defer type="text/javascript" ...
<script async defer type="text/javascript" ...

The charset attribute is not valid for inline scripts:
"Element script must not have attribute charset unless attribute src is also specified."
http://dev.w3.org/html5/markup/script.html

Bumped django dependency

First example should probably say PipelineStorage

Fix incorrect PIPELINE_JS_COMPRESSOR setting in documentation

Adding a new company on the documentation (fixes #309).

The current code inserts bytes into a string. In Python 3 those are different types, causing the URI to look like:

    url("data:image/png;charset=utf-8;base64,b'iVBORw0KGgoAAAANSUhEUgAAAA...'")

Because Base64 data is always ASCII it is safe to decode it as such, and insert the resulting string, which causes the correct output:

    url("data:image/png;charset=utf-8;base64,iVBORw0KGgoAAAANSUhEUgAAAA...")

First example in documentation should refer to ordinary PipelineStorage rather than PipelineCachedStorage, which is covered in the "Cache-busting" section below.

Do not rewrite data URIs

Fixed spelling of my last name

If multiprocessing and concurrent unspported, render linear compilation.

Use generators and add a gzip support.

Signed-off-by: Timothée Peignier <timothee.peignier@tryphon.org>