Restructuring Python bindings, moved submodules and dependencies to own folders, added dependency checking for some tutorials, minor refactorings

Former-commit-id: 2214125878

python/tutorial/shared.py

@@ -0,0 +1,16 @@
+import pyigl as igl
+import sys
+
+
+TUTORIAL_SHARED_PATH = "../../tutorial/shared/"
+
+def check_dependencies(deps):
+    available = [hasattr(igl, m) for m in deps]
+    all_available = True
+    for i, d in enumerate(available):
+        if not d:
+            all_available = False
+            print("The libigl python bindings were compiled without %s support. Please recompile with the CMAKE flag LIBIGL_WITH_%s." %(deps[i], deps[i].upper()))
+
+    if not all_available:
+        sys.exit(-1)