Reduce duplicate code in CssAbsolutizingTestCase
Fix #467: Remove unnecessary checks (filename in COMPRESS_ROOT, or existence of file) in CssAbsoluteFilter
Fix: compressor.filter.base Nullify self.type for Specializations to filter_type
Updated badges to be SVG and added Python3 port badge.
Fixed one badge that doesn't provide SVG.
Merge pull request #479 from iknite/fix_filter_base

Fix FilterBase clears self.type for subclasses
Use get_template() when dealing with django templates
Merge pull request #524 from diox/use-get-template

Use get_template() when dealing with django templates.
Add support for COMPRESS_CSS_HASHING_METHOD = None
Fix cache backend for 1.7 compatibility (locmem:// has been deprecated for a while)
Merge pull request #526 from diox/css-hashing-method-none

Add support for COMPRESS_CSS_HASHING_METHOD = None
Fix link markup
Merge pull request #530 from merwok/patch-1

Fix link markup
Update usage.txt
Merge pull request #539 from alimony/patch-1

Fix typo
Merge pull request #471 from agriffis/CssAbsoluteFilter-skip-filename-check

Remove unnecessary filename and existence checks in CssAbsoluteFilter
Update test_css_no_hash pursuant to changes in CssAbsolutizingTestCase from 626bc52007378bedb39a40f4a0334f0e20ba49f6.
Types at readme (-engine should be --engine)
Merge pull request #540 from lukaszb/patch-2

Types at readme (-engine should be --engine)
Apply shell quoting to infile/outfile. #536