Decrease USB buffer overflow timeout to 1ms from 10ms.

git-svn-id: http://ninja-scan-light.googlecode.com/svn/trunk@157 94d2995a-3457-b8a5-7510-40b377e6a921
Correct comments.

git-svn-id: http://ninja-scan-light.googlecode.com/svn/trunk@158 94d2995a-3457-b8a5-7510-40b377e6a921