Elaborate the root .gitignore

The gitignore  now contains  endings of common  executable and  object
code files on Windows  and Linux, as well as  some image file  endings
and, for the sole need of being complete, moving picture file endings.

.gitignore

@@ -1,4 +1,27 @@
 
-/.private/
-/.build/
-/voxula
+# Hidden folders
+/.*
+*/.*
+
+# Unixoid executables (ELF format)
+*.a
+*.elf
+*.o
+*.so
+
+/voxula
+
+# Windows Executables (COFF/PE-format)
+*.dll
+*.exe
+*.lib
+
+# Images
+*.bmp
+*.jpeg
+*.jpg
+*.png
+
+# Moving Pictures
+*.avi
+*.mp4