Added a servlet to send message.

Fixed a bug in firefox web browsers.
It seems GAE doesn't support Base64 email attachment.
Added new functions for the last version
After the shower tub is drawn, you can place a grid (a small circle)
Now you can draw the grid and set the measures. Use the key "Intro" to
set the measures.
Merge pull request #2 from ervitis/nightly

Pull request 2