Log Message:
Update security/py-ecdsa to 0.11

Upstream changes:
-----------------

* Release 0.11 (10 Mar 2014)

Add signature-encoding functions "sigencode_{strings,string,der}_canonize"
which canonicalize the S value (using the smaller of the two possible
values). Add "validate_point=" argument to VerifyingKey.from_string()
constructor (defaults to True) which can be used to disable time-consuming
point validation when importing a pre-validated verifying key. Drop python2.5
support (untested but not explicitly broken yet), update trove classifiers.