Add support for exclude function

[falkenbt]

Not sure if this is currently possible due to the double quotes required by exclude. Is there a way to escape quotes from the :data definition?

From the graphte doc:
exclude(seriesList, pattern)

Takes a metric or a wildcard seriesList, followed by a regular expression in double quotes. Excludes metrics that match the regular expression.

[ripienaar]

Well its just ruby strings, so standard ruby quote escaping would probably work

[falkenbt]

In this case this does not work (at least I couldn't get it to work) because you end up with something like exclude(seriesList, "myregex") but it should look like exclude(seriesList, "\myregex").

[davewongillies]

You'll need to escape the double quotes and the backslashes, so I'd expect it to look like exclude(seriesList, \"\\myregex\\\")