Add a few normal examples of using the NeoBundle command
Remove install example of vimproc

It's a good example of what NeoBundle can do, but I think it distracts from
NeoBundle's basic usage, which is what this example sample vimrc is.
Add more description to NeoBundleCheck
Specify what vimrc commands are required
Add How it works section to README
Move useful commands out of sample vimrc
Point to the help files
Remove unneeded text from sample vimrc
Remove unneeded Docs section
Move advantages section down
Change format of Advantages section
Improve wording of Advantages section
Merge pull request #204 from AndreZSanchez/readme-1

Improve README