CMP0007
-------

list command no longer ignores empty elements.

This policy determines whether the list command will ignore empty
elements in the list.  CMake 2.4 and below list commands ignored all
empty elements in the list.  For example, a;b;;c would have length 3
and not 4.  The OLD behavior for this policy is to ignore empty list
elements.  The NEW behavior for this policy is to correctly count
empty elements in a list.

This policy was introduced in CMake version 2.6.0.  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.