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.

resources/localization/CMakeLists.txt

@@ -0,0 +1,8 @@
+set(L10N_DIR "${PROJECT_SOURCE_DIR}/resources/localization")
+add_custom_target(pot
+    COMMAND xgettext --keyword=L --from-code=UTF-8 --debug
+        -f "${L10N_DIR}/list.txt"
+        -o "${L10N_DIR}/Slic3rPE.pot"
+    WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
+    COMMENT "Generate pot file from strings in the source tree"
+)