Trivial git script fixups

Fix permissions, and add trivial "reset" and "add" scripts.

The "reset" script just resets the index back to head, while the "add"
script is just a crutch for people used to do "cvs add".
diff --git a/git-reset-script b/git-reset-script
new file mode 100755
index 0000000..eaefd00
--- /dev/null
+++ b/git-reset-script
@@ -0,0 +1,3 @@
+#!/bin/sh
+git-read-tree --reset HEAD
+git-update-cache --refresh