Details:
==========

 - New cpack_add_component, cpack_add_component_group, and
cpack_add_install_type "commands" defined as macros in the CPack
module.
 - Documentation for all of the variables and commands in the CPack module.
 - Added get_cmake_property(... COMPONENTS) to CMake to ask for the
names of all components. Used in the CPack module to automatically
build component-based installers. (Set CPACK_MONOLITHIC_INSTALL to
turn off component-based installation).
 - A group can declare its PARENT_GROUP, to build an arbitrary
hierarchy of groups.
 - New CPack command cpack_configure_downloads, which creates an
installer that downloads only the selected components on-the-fly.
Those components marked DOWNLOADED will be separate packages
downloaded on-the-fly (or, all packages can be marked as such with the
ALL option to cpack_configure_downloads). Individual components are
compressed with ZIP at installer-creation time and
downloaded/uncompressed by the installer as needed. This feature is
only available on Windows with NSIS at the moment.
 - NSIS installers can install themselves and enable the "Change"
button in Add/Remove programs, allowing users to go back and install
or remove components. This can be disabled through
cpack_configure_downloads, because it's only really useful is most of
the application's functionality is in downloaded components.
 - Bug fix: automatically install everything whose COMPONENT was not
specified (it's a hidden, required group)
 - Bug fix: fixed removal of components when re-running the NSIS
installer and unchecking components
 - Bug fix: NSIS installers now only install/remove the minimal
number of files when re-run to update the installation (or by clicking
"Change" in Add/Remove programs)