shared disk size and gitignore

I'm got a development branch where I'm experimenting with different shared disk sizes and different versions of the database.  Found that depending on my value of shared disk size, sometime ruby puts a decimal on it which breaks Oracle VM.  Found a very generic fix which is included in this patch.

Also, added a generic gitignore line for patch files.  Both of these changes seemed pretty non-controversial, so sending you a quick pull request now!