scons: Build progs.

Just demos and trivial dirs for starters.
diff --git a/.gitignore b/.gitignore
index d519cab..1c3d446 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,10 +1,15 @@
 *.a
+*.dll
+*.exe
+*.ilk
 *.o
+*.obj
+*.pc
+*.pdb
 *.pyc
 *.pyo
 *.so
 *.sw[a-z]
-*.pc
 *~
 depend
 depend.bak
@@ -16,6 +21,6 @@
 config.log
 config.status
 cscope*
-.sconsign*
+.scon*
 config.py
 build