Fixed/Added ignore rules

- *.ses files are generated by Freerouting (which is the partially integrated autorouter)
- *.dsn files weren't actually being ignored

KiCad.gitignore

@@ -13,7 +13,8 @@ _autosave-*
 *.net
 
 # Autorouter files (exported from Pcbnew)
-.dsn
+*.dsn
+*.ses
 
 # Exported BOM files
 *.xml