[CMake] More control over CPACK_NSIS_MODIFY_PATH

[Bart Janssens]

Hi all,

Currently, setting CPACK_NSIS_MODIFY_PATH to "ON" creates options in
the generated NSIS installer to allow the user to choose how to add
the path, i.e. don't add, add for current user or add for all users.

I have a project that always needs to be added to the path for all
users. Would it be acceptable to change the behavior of
CPACK_NSIS_MODIFY_PATH so it accepts 4 values:
OFF: Don't modify the path
ASK: Current "ON" behavior, i.e. options in the installers
ALL: Add to system path (all users) without asking in the installer
CURRENT: Add only for current user without asking in the installer

On a related note, the current behavior when choosing the "all users"
option in the generated installer appears to be broken, see
http://public.kitware.com/Bug/view.php?id=8177 for details and a
patch.

Kind regards,

-- 
Bart Janssens