removed redundant indirection layer
ROOT-free version (no auto loading)
reorganized the code

- added the namespace and the include directory Gaudi
- separated the public header from the internal details
stub for an auto loading mechanism
added a small application to dump the list of factories per lib

The application 'listfactories' take a list of libraries on the command
line and reports the factories in each of them in the format

    library:factory

one factory per line.
use the extension .cpp for C++ sources (Gaudi conventions)
rewritten the mechanism to locate and load factories
added code to get the list of factories from *.components files

At construction, the plugin service registry looks for all the
*.components file in the LD_LIBRARY_PATH and fills the internal cache.
use the term "components" instead of "factories"
added licence and copyright notice