Log Message:
Update to 1.7.11
Update LICENSE

Upstream changes:
Changes in Version 1.7-11

  o Extended the license from "GPL-2" to "GPL-2 | GPL-3".

  o Avoid duplications in Suggests/Imports/Depends in the package's
    DESCRIPTION. Use only :: instead of ::: to access certain functions
    from other namespaces.

  o Added as.list() methods for yearmon/yearqtr.

  o Added workaround in Ops.zoo if first argument is not a zoo series
    (prompted by Josh Ulrich).

  o The transform() method for zoo series now does what method for
    data.frame does (instead of just calling it) in order to get
    non-standard evaluation.