Merge pull request #30 from smeranda/master

Updates to external page link functionality
add a scannable field to the assessment table
Log scannability of a page
return scannable in json
correctly count the total number of pages
update phpdoc
Do not check links to ids on the same page
always close the curl handle
Improve speed and memory useage by only requesting the header
Don't apply text-shadow to .wdn_notice
add an error_scanning var to the site json output
display site check errors
update css
update the spider
add queue info to the db
Add a user queue script
update the api documentation
add info about cron to readme
Poll the server to check the status of the queue
Merge pull request #35 from unl/issue-18

Implement a queue