Help: Add documentation on escaping changes with CMP0053
EVIS: Fix CMAKE_CURRENT_LIST_LINE
Help: Revise variable reference syntax in cmake-language.7
Help: Fix CMP0053 reference to cmake-developer.7 manual
EVIS: Initialize t_lookup members
EVIS: Disallow literal () in ENV variables
tests: Test other escape patterns
tests: Test NUL and parentheses in CMP0053

Also remove them from StringFileTest since they belong in Syntax.
Windows: Avoid () in environment names

Use a redirection.