Fixed/Updated Insert Image

I fixed a problem where the src for new images was
"null/img/blank.jpg". I also added a new config parameter called
"defaultImageSrc". This will allow users to specify their own defaul
image for inserts. Also, cleaned up the imagesstyle code. Was not
checking for numeric values and also did not take in account min values.
Formating and Config issues

Fixed some JSLint "warnings" and fixed a problem with some config
variables.