Ignore Clipper, libpng, mcut and Boost.Polygon Internals in clang-tidy

Each only works through a wrapper or umbrella header: libslic3r/clipper.hpp or clipper_z.hpp configure Clipper before including it, png.h pulls in libpng's config headers, and Boost.Polygon's headers only compile through polygon.hpp or voronoi.hpp.

.clang-tidy

@@ -10,6 +10,9 @@ CheckOptions:
   # GTK or pthread one), library internals and forward declarations, CPython's
   # headers behind Python.h, curl's behind curl.h, oneTBB's behind tbb/, and
   # admesh's stl.h, which the include path also exposes without its directory.
+  # Clipper's own clipper.hpp is only included through libslic3r/clipper.hpp or
+  # clipper_z.hpp, which configure it first, and Boost.Polygon's headers only
+  # work through boost/polygon/polygon.hpp or voronoi.hpp.
   # FFmpeg's C headers are left alone because they are only included inside
   # extern "C", which an inserted include would miss. OS-specific headers (GLib,
   # GTK, D-Bus, POSIX, the Windows SDK) are only used inside platform #if blocks,
@@ -44,4 +47,8 @@ CheckOptions:
     fcntl\.h;
     termios\.h;
     [/\\](um|shared)[/\\].*;
-    sal\.h
+    sal\.h;
+    clipper[/\\]clipper\.hpp;
+    png(lib)?conf\.h;
+    mcut[/\\]platform\.h;
+    boost[/\\]polygon[/\\].*