add git-foo, which lists new and modified files from git

Signed-off-by: Colin McCabe <cmccabe@alumni.cmu.edu>

diff --git a/git-foo b/git-foo
new file mode 100755 (executable)
index 0000000..476edd2
--- /dev/null
+++ b/git-foo
@@ -0,0 +1,3 @@
+#!/bin/bash
+
+git status | egrep '(modified:)|(new file:)' | sed 's/.*://'