The find_package command already knows how to compute installation
prefixes from PATH. Use the same approach to establish prefixes for
find_library, find_file, and find_path to use to look in directories
like "<prefix>/lib[/<arch>]" and "<prefix>/include" for libraries and
headers. This will reduce the amount of configuration end users need to
do to establish a work environment rooted under a specific prefix.
Manage classes of search paths in labeled containers. This removes the
need to have a seperate member variable for each type of search path, but
also allows path types to be grouped togethor in various different ways
and manipulated as subsets of the full set of search paths.
The functions for adding the various different types of paths have been
factored out into a new class, cmSearchPath. It is to be used as a helper
container class for the various find_* commands.