minor refactoring of duplicated currency code
relying on the internal account key when possible
updated soa
Empty segments during filtering will no longer be treated as if it was
not present.
Removed the deprecated tagId field in the agent's creative configuration.
added random user ids to avoid being frequency-cap after 42 bids
Basic framework for testing static filters.
Segment filtering on an empty list now takes the include list in
account.

If we're filtering an empty segment list then the outcome depends on
whether we have elements in the include list or not. If the include
list is not empty then the bid request should be filtered out
otherwise it should be filtered in.
Allow short account keys
Remove unneeded assertions
Merge pull request #53 from dohse/allow-shorter-account-key

Allow short account keys
Merge pull request #54 from dohse/remove-superfluous-assertions

Remove unneeded assertions
Merge pull request #4 from rtbkit/master

sync with upstream