try to restore pypy tests
Fixed XXE flaw in sitemap reader
Merge pull request #674 from dangra/pypy

[WIP] try to restore pypy tests
Run testsuite with py.test
Fixed XML selector against XXE attacks
Added test against XXE attacks for Sitemap
Added resolve_entities to kwargs in SafeXMLParser
 Trial functionality for running tests with pytest

  * Change current dir to tmp dir on each test run
  * Log twisted with test.log
Add py33 environment to allowed failures in travis-ci
Support doctest and __init__.py test discover in pytest
Ignore files with import errors on pytest test discover
Change function name so it does not mess up with pytest autodiscover
Fix httpcache doctest that assumed dictionary order
Ensure spiders module reload between spider manager tests
Merge pull request #676 from csalazar/fix_xxe_flaw

Fixed XXE flaw in sitemap reader
Merge pull request #679 from Curita/pytest

Run tests with pytest instead of trial
New tox env: docs
Ignore known broken links in docs linkcheck
Fix broken links in documentation
Merge pull request #687 from Curita/docs-linkcheck

Docs build and linkcheck in tox env