Add support for normalized calculations

[stronk7]

To avoid some real noise in indicators we are applying a outlier-detection technique (1.5xIQR) and proceeding to normalize them using a pseudo avg that will fit always within the expected values.

Note we don't apply the outlier algorithm recursively neither any other detail. Just 1-pass normalization of noise values.

While 1.5 is a generally accepted value, if we detect that too much is being normalized, we can always go up to 2.3 to just normalize "very rare" outliers.

By default, it's disabled, so everything continues working 100% the same. Only under demand it will become enabled.

You can enable it by adding n=1 or n=true to the url.

At the same time, a bunch of rounding errors have been fixed, display is always with 2 decimal digits but all average calculations are performed with full resolution.

Other small changes are:

• Added support to https.
• Improve red/green and signed display.
• Fix images overlay.

[sarjona]

Eloy, thanks for this nice and helpful improvement. I've reviewed the patch and I haven't seen anything wrong there so I'm happy to integrate it! :-)