Control the root directory of the default directory presented to
the end user of an NSIS installer by a CPack variable.
Previously, the value used in the NSIS script was $PROGRAMFILES,
which is equivalent to the "ProgramFiles" environment variable.
That default value is still the same, but now a project may
override the value by setting this new variable.
Previously, only strings containing "http:" qualified as
URLs when found in CPACK_NSIS_MENU_LINKS. Now, we use a
regex to detect strings beginning with any of the following:
ftp://
ftps://
http://
https://
news://
mailto:
This commit also moves the caller of CreateMenuLinks outside
the "if (cpackPackageExecutables)" block, allowing clients to
use CPACK_NSIS_MENU_LINKS without also having CPACK_PACKAGE_EXECUTABLES
defined. That bit of this commit fixes the remainder of the
issue described in http://public.kitware.com/Bug/view.php?id=7828
Also, added a set(CPACK_NSIS_MENU_LINKS ...) to the CPackComponents
test to enable verifying that all of this actually works.