Add block title and dimensions to placeholder text

Hi,
I have a little enhancement to assist ad placement during development. I found it helpful for the placeholder text to include the block title and the dimensions, particularly when you have several blocks all designed for specific places on your site, using different visability settings. Having the title and dimensions makes it easier to see exactly which blocks are being shown in which locations.

There is one change in adsense_managed_block to add the title to the returned arry, and there is one change in adsense_display which adds the title (if available) and adds the dimensions if these are not already included in the title or description.

Patch coming up.