Added code to shift decimal points onto the previous character if possible

Rather than taking up a full character with a decimal place the attached code will shift the decimal point onto the character to the left if possible.  It is not possible if the decimal is the first character on the display, or if the previous character has already had a decimal point shifted onto it.

It is the difference between this:
![imag0426](https://f.cloud.github.com/assets/218403/662734/2cd28332-d75d-11e2-871f-3f3239cfcfb8.jpg)
And this:
![imag0425](https://f.cloud.github.com/assets/218403/662735/312a348e-d75d-11e2-930f-9bc70958cef1.jpg)