Update setup.py to use Pillow rather than PIL

PIL is old and broken, using Pillow instead to support modern systems.
Merge branch 'patch-1' of https://github.com/bradleyayers/xhtml2pdf into bradleyayers-patch-1

Conflicts:
	setup.py
Changed PIL to PIllow in requirements.txt

Also renamed requirements.xml to requirements.txt.
Added _trial_temp to gitignore.
Bumped version to 0.0.5, changelog.
Added next version changelog entry.
Added letter-spacing property.
Enhancements to barcodes:
- Added checksum as option (already supported by report lab).
- Switched humanreadable to use int() to make the conversion to attribute, so you can specify humanreadable="0" and it works as expected.
Merge pull request #91 from photojosh/master

Updated barcode rendering with option for checksum, enhanced humanreadable
Merge pull request #87 from trib3/master

Prevent errors when weird images are encountered
Merge pull request #95 from tachang/letter-spacing

Added letter-spacing property.
Added Jeff to AUTHORS. Thanks a lot!
embedding images now works in jython
Merge pull request #96 from beachmachine/master

Fix for images in Jython
Added Andreas to AUTHORS! Thanks for your contribution.
added tag-name to the css cache-key
Merge pull request #97 from beachmachine/master

Added tag name to css cache-key
fix for 8-bit PNGs
Merge pull request #99 from beachmachine/master

Fix for 8-Bit PNGs
PmlImageReader's __str__ method always returned the same string on jython