Add raw_value key to redis and simplify POST

I'm sorry for mixing two different things in one commit and I promise I'll never
do that again, but I don't have much time.

I'm adding a raw_key to Redis so that we don't loose this information after performing
the window averaging.

Maybe we should remove this average window thing, I'm not sure it's so useful.
Added info about raw_value in model_input

Our model_input now needs three components: raw_value, value, time.

Value is the value to be passed do NuPIC, so it can be an average.
Raw value is the original value.
Added raw_value key to model_input

Now we are passing the raw metric value together with the average one to
model_input
Added raw_value key to model_input

Now we are passing the raw response time to model_input, as we are passing
just the average before.
Added new raw_value key to results JSON

We'll use it to plot the raw values instead the average ones, as the previous
way was confusing.

I was confused when interpreting the charts, because when averaging we see some
plateaus that is an artifact of the method.
Added debug URL parameter

If debug=true we show raw_value, average_value and predicted, otherwise we only
show raw_value.

Likelihood and anomaly are always shown.
Added debug URL parameter info
Changed some colors.
Forgot to update new_data to pass raw_value
Added favicon.
Added link to favicon.
Title now is OMG Monitor.
Title is now OMG Gauge.
Escape special characters in chart's div id

I've found a problem when the monitors ID contains dot (like in "cw.sa-east").
The solution was to escape special characters in the ID:
http://stackoverflow.com/questions/605630/how-to-select-html-nodes-by-id-with-jquery-when-the-id-contains-a-dot
Change cpu variable, as it's a general metric now.
Added generic transform method

Instead of calling moving_average() when streaming data to NuPIC, we call
transform() method. We have also included an update() method, so transform has
two possible data transformations by now:
* moving_average: smooth data by moving_average_window before passing to NuPIC
* scale: scale data by scaling_factor before passing to NuPIC
Get display_names and use _transform()

We have a more general _transform() method call before sending data to NuPIC.

We also can get the name of some Librato sources now.
Using new _transform() method

Instead of calling _moving_window_average() we now call generic _transform()
method.

This allow us to do other kinds of transformations before sendind data to NuPIC.
Added new transform and scaling config

We also don't need moving_average_window to be passed, so it's optional now.

We accept a new configuration `transform`, which can be moving_average or scale.
Renamed average_value field to transformed

This reflects the latest changes on streams, allowing other transformations
besides moving_average.