Help: Document SYSTEM treatment of IMPORTED target INTERFACE_INCLUDE_DIRS

Document how the behavior can be controlled.
Help: Add additional hyperlink targets
Qt4: Add IMPORTED executable for qmake.
CMP0028: Trigger on libraries from INTERFACE of dependencies.
CMakeLists: Generate the cmCommands.cxx file.

Define the list of commands in the CMakeLists.txt file. List the
sources in the CMakeLib target, but mark them as HEADER_FILE_ONLY.
This has the effect that IDEs will show the files, though they
will not be built again.

Add a cmCommandsForBootstrap.cxx file for bootstrapping purposes.

Rename the cmExportLibraryDependencies file to match the common
pattern.
Remove the Example from the source.

It is not showing modern practice, and is obsolete as documentation
after the rst documentation system and new content.
Export: Use a macro to ensure minimum development version requirement

Use the version number of the specified release, or of the current
development version if the release is not yet made.
Help: Don't list debuggable properties in cmake-buildsystem manual.
Merge topic 'Qt4-qmake-IMPORTED'

7d90d6c5 Qt4: Add IMPORTED executable for qmake.
Merge topic 'fix-CMP0028-iface'

b2915238 CMP0028: Trigger on libraries from INTERFACE of dependencies.
Merge topic 'generate-cmCommands-file'

23d3d38a CMakeLists: Generate the cmCommands.cxx file.
Merge topic 'remove-Example'

2e615d4b Remove the Example from the source.
Merge topic 'cmake-devel-version-macro'

eaf703f1 Export: Use a macro to ensure minimum development version requirement
Merge topic 'extend-docs'

0b3e98d9 Help: Don't list debuggable properties in cmake-buildsystem manual.
39d08b92 Help: Add additional hyperlink targets
ef17e293 Help: Document SYSTEM treatment of IMPORTED target INTERFACE_INCLUDE_DIRS