Added the "test" target to execute the perl prove unit / integration tests. Added a post-build step to copy the XS.dll & Slic3r/XS.pm to local-lib.
cleanly on Windows & Linux. There is still a work on OSX: The XS module has to be linked without perl.lib and with the following parameters to produce a bundle: -bundle -undefined dynamic_lookup
FindAlienWx.cmake and FindPerlEmbed.cmake for easier Perl integration.
