Class that identified tokens which should not be passed down the entire term pipeline, and instead
passed onto a specified stage instead. Tokens are autmatically lowercased if lowercase
is set (as it is by default). If no tokens are specified, then no tokens are omitted from the term
Instantiate this object, using properties to define tokens. Skip tokens are
specified as a comma delimited list, using the termpipelines.skip
property. Terms are lowercased if lowercase is set (as it is by default).