Fix error in :Helptags

Error happens if ~/.vim/doc/ doesn't contain
any files, but contain some subdirectories.
Fix the URL that GitHub broke

Closes #61.
Fix :V* commands when file isn't found
Fix :Vopen tab complete of a/b on Windows

Closes #70.
Simplify modeline
Drop wget from install instructions

Who's in the wget-but-not-curl boat, anyways?
Don't override existing :Vedit commands

Guess what my next plugin is going to be.
Promote scriptease.vim
Remove advice around filetype on

Closes #80.
Allow for :exe pathogen#infect()

Idea: Return 'finish' here if an environment variable says to skip the
rest of the vimrc.
Change :call to :execute

I have some ideas about uses for this, such as returning :finish if an
environment variable tells us to skip the vimrc.
Plug sensible.vim
Allow disabling absolute path
Formally deprecate :Vopen family
Allow/encourage infect paths ending in /{}

I want to break this API.
Rename pathogen#runtime_append_all_bundles

Better a cute name than a verbose yet still cryptic one.
Introduce pathogen#surround()
Actually try things before you commit
Fix typo
Fix missing fold marker