added element class stub
added test case stub
added method stubs
added test stubs
moved test initialization to correct class
added comments
implemented tests
implemented validation in URL element
added test that reveals a problem with element attributes
fixed attribute problem, added note
changed wording
added call to parent init() method for consistency between elements
added test stubs
added comments
introduced constant for the name of the hostnames attribute
implemented tests
added hostnames attribute
URL validator: renamed acceptedHostnames to allowedHostnams to be consistent with naming in form elements
renamed constant
added test stubs