CMP0045
-------

Error on non-existent target in get_target_property.

In CMake 2.8.12 and lower, the :command:`get_target_property` command accepted
a non-existent target argument without issuing any error or warning.  The
result variable is set to a ``-NOTFOUND`` value.

The OLD behavior for this policy is to issue no warning and set the result
variable to a ``-NOTFOUND`` value.  The NEW behavior
for this policy is to issue a ``FATAL_ERROR`` if the command is called with a
non-existent target.

This policy was introduced in CMake version 3.0.  CMake version
|release| warns when the policy is not set and uses OLD behavior.  Use
the cmake_policy command to set it to OLD or NEW explicitly.