#135 #141 2 deduplication fixes for the website agent

Fix 1) #135 update events' expiry date on deduplication

Previously events would age out even when being de-duplicated
frequently, resulting in spurious identical events making their way to
the next agent in the pipeline. This isn't the most efficient code (same
as previously), but not worth optimizing further until we've decided
what to do with a more generic deduplication module

Fix 2) #135 set deduplication "look back" to be configurable (and
default to a large number)

I think this is preferable default behavior? Potential performance
issues should be addressed via an efficient deduplication library using
indexed DB fields
#154 Improvements to website deduplication logic

as discussed with @cantino
#154 Fixed indentation (website deduplication improvements)

Pesky siren tab key calling out to me as I type!
Merge branch 'website_deduplication_improvement' of https://github.com/Alex-Ikanow/huginn into Alex-Ikanow-website_deduplication_improvement
minor code cleanup
default is all
Merge pull request #164 from cantino/Alex-Ikanow-website_deduplication_improvement

Alex ikanow website deduplication improvement