fixed the exception when scheduler string was processed

the `ImproperlyConfigured` exception with " Wrong context definition format: "MIN_TIME": 15,... " error will be raised even the default scheduler setting was used, the reason is that the CRLF sometime isn't '\n' but '\r\n'
Hint on DDS not working with Scrapy 0.18 in docs
Merge pull request #27 from zzpwelkin/patch-1

fixed the exception when scheduler string was processed
Allowed Checker Reference URLs (models.Scraper) to be longer than 200 characters (DB change, migration)
Merge branch 'master' of github.com:holgerd77/django-dynamic-scraper

Conflicts:
	dynamic_scraper/migrations/0004_auto__chg_field_scraper_checker_ref_url.py