WIP: Moved sources int src/, separated most of the source code from Perl.

The XS was left only for the unit / integration tests, and it links
libslic3r only. No wxWidgets are allowed to be used from Perl starting
from now.

src/libnest2d/cmake_modules/FindClipper.cmake

@@ -0,0 +1,50 @@
+# Find Clipper library (http://www.angusj.com/delphi/clipper.php).
+# The following variables are set
+#
+# CLIPPER_FOUND
+# CLIPPER_INCLUDE_DIRS
+# CLIPPER_LIBRARIES
+#
+# It searches the environment variable $CLIPPER_PATH automatically.
+
+FIND_PATH(CLIPPER_INCLUDE_DIRS clipper.hpp
+    $ENV{CLIPPER_PATH}
+    $ENV{CLIPPER_PATH}/cpp/
+    $ENV{CLIPPER_PATH}/include/
+    $ENV{CLIPPER_PATH}/include/polyclipping/
+    ${PROJECT_SOURCE_DIR}/python/pymesh/third_party/include/
+    ${PROJECT_SOURCE_DIR}/python/pymesh/third_party/include/polyclipping/
+    ${CMAKE_PREFIX_PATH}/include/polyclipping
+    ${CMAKE_PREFIX_PATH}/include/
+    /opt/local/include/
+    /opt/local/include/polyclipping/
+    /usr/local/include/
+    /usr/local/include/polyclipping/
+    /usr/include
+    /usr/include/polyclipping/)
+
+FIND_LIBRARY(CLIPPER_LIBRARIES polyclipping
+    $ENV{CLIPPER_PATH}
+    $ENV{CLIPPER_PATH}/cpp/
+    $ENV{CLIPPER_PATH}/cpp/build/
+    $ENV{CLIPPER_PATH}/lib/
+    $ENV{CLIPPER_PATH}/lib/polyclipping/
+    ${PROJECT_SOURCE_DIR}/python/pymesh/third_party/lib/
+    ${PROJECT_SOURCE_DIR}/python/pymesh/third_party/lib/polyclipping/
+    ${CMAKE_PREFIX_PATH}/lib/
+    ${CMAKE_PREFIX_PATH}/lib/polyclipping/
+    /opt/local/lib/
+    /opt/local/lib/polyclipping/
+    /usr/local/lib/
+    /usr/local/lib/polyclipping/
+    /usr/lib/polyclipping)
+
+include(FindPackageHandleStandardArgs)
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(Clipper
+    "Clipper library cannot be found.  Consider set CLIPPER_PATH environment variable"
+    CLIPPER_INCLUDE_DIRS
+    CLIPPER_LIBRARIES)
+
+MARK_AS_ADVANCED(
+    CLIPPER_INCLUDE_DIRS
+    CLIPPER_LIBRARIES)