add interface for new email provider apis, docs on mg api
unsubscribe management things
new campaign content validator to fix non-validating email
hint at server host value for system variables
adding legend keys for campaign content
more documentation and cleanup
Merge branch 'dev' of https://github.com/eBrian/hypermailer into dev
adding legend keys for campaign content
adding changes to web view and campaign variables
Merge branch 'dev' of https://github.com/eBrian/hypermailer into dev
adding legend key variables for campaign
new base sql, tags added, content fixed