[breadcrumbs] better handling of invalid crumbs
[breadcrumbs] better handling of invalid crumbs

- dont throw away entire interface due to a bad crumb
- gracefully handle invalid data on individual crumbs

BuildingLink/sentry,fotinakis/sentry,gencer/sentry,JamesMura/sentry,zenefits/sentry,zenefits/sentry,jean/sentry,mvaled/sentry,ifduyue/sentry,beeftornado/sentry,jean/sentry,looker/sentry,gencer/sentry,BuildingLink/sentry,looker/sentry,fotinakis/sentry,beeftornado/sentry,JackDanger/sentry,ifduyue/sentry,alexm92/sentry,mvaled/sentry,jean/sentry,JackDanger/sentry,beeftornado/sentry,JamesMura/sentry,jean/sentry,mvaled/sentry,gencer/sentry,jean/sentry,BuildingLink/sentry,looker/sentry,BuildingLink/sentry,mvaled/sentry,looker/sentry,alexm92/sentry,JamesMura/sentry,ifduyue/sentry,looker/sentry,JackDanger/sentry,mvaled/sentry,ifduyue/sentry,fotinakis/sentry,zenefits/sentry,ifduyue/sentry,mvaled/sentry,JamesMura/sentry,alexm92/sentry,zenefits/sentry,gencer/sentry,JamesMura/sentry,fotinakis/sentry,gencer/sentry,zenefits/sentry,BuildingLink/sentry