Merge pull request #23 from andresp99999/hcf-middleware

Hcf middleware
Rename hs_lost to hs_consume_from_slot
Add HS_START_JOB_ENABLED setting, clean up the start job related documentation
Fix bug on starting new job, removing line using non existing job
Fix issue of endless loop when the frontier was empty and the middleware continue starting new jobs
Log an error message when processing a non GET request with the use_hcf key set.
Merge pull request #24 from andresp99999/hcf-middleware

Hcf middleware
Fix for issue with missing logger for 'hubstorage.batchuploader'
Merge pull request #25 from andresp99999/hcf-middleware

Fix for issue with missing logger for 'hubstorage.batchuploader'
Don't send duplicated links to the HCF
Merge pull request #26 from andresp99999/hcf-middleware

Don't send duplicated links to the HCF
way to get settings improved
fix recommended scrapylib.crawlera import path
Merge pull request #28 from nramirezuy/hcf_get_settings

way to get settings improved
do not touch slot delay if crawlera mw is disabled