removing the fudge factor [the wrong thing to do]

Instead we should allow receiving events without a timestamp. This is
specially important for Absolute metric which will be used to counte
how many times a single event repeated
removing the deprecated /v1/range [which bring us to v3]
single quote (') is now also available to quote strings
deprecating PUT /v1/data/:key in favor of POST and accepting a list of values

The reason we deprecated PUT method is that the timestamp is
optional. Thus, idempotency no longer holds.
writing tests for POST /v1/data/:key
http protocol is now read/write: you can write metrics using http protocol
v3.0.0 release
bugfix: removing etag from response
adding "cache-control: max-age=300; public"
cassandra now have its own section on config file
adding --probe-services. The idea is to able to skip tests depending on the environment
using one columnfamily per month
v3.1.0
bugfix: using self.write_error instead of raise and write_error now sets the http status code properly
using snappy compression and increasing sstablesize
embedding python-twisted and python-wokkel as debian stable provides no suitable version
no longer treating all exceptions the same: depending on the exception class we may reaply 400, 404 or 500
v3.2.0
testing leela http error codes