[administrivia] Add .gitignore files, based on .cvsignores.
diff --git a/ports/.gitignore b/ports/.gitignore
new file mode 100644
index 0000000..73bcf19
--- /dev/null
+++ b/ports/.gitignore
@@ -0,0 +1,3 @@
+.arch-inventory
+.arch-ids
+