Clean the living crap out of Views's help text

I was asked to take a stab at this by Earl in preparation for RC1. Here's an initial patch.

Problems that I found in my first pass:
1. Link to "add new view" was missing a target="_blank" so it didn't open up in the help window.
2. LOTS of inconsistencies in formatting. Single vs. double quotes, strong vs. em, etc.
3. Sometimes they're told what button to click when they're done, sometimes they're not.
4. Button / option names have changed in a few places.
5. "Create a block to list recent story nodes" just says "TODO" :( This one I couldn't fix.

Regarding #2, I reformatted the text essentially with the following guidelines:
- If the interface text is bolded, it got strong tags.
- If it's a button they need to click, that's bold too.
- If the text is not bolded (ex: links to click, options to check), it got italicized.
- If it's user-entered text it got 'single quotes'.

This still needs lots of work.

Furthermore, I feel like this is missing a lot of "Why" vs. "Just blindly follow my instructions, and hopefully you figure it out." I can work on this some but not by tomorrow. :( I would highly recommend postponing string freeze until a later RC. Since this help text is going to be here for the entirety of the Views 2 release, it's very important that we get it right.