Initialize the repo
Attribute to Tim Pope

I've used some of defaults from vim-sensible, and this project is definitely
inspired by Tim Pope's great job. So I've added an attribution on the top of
the file.
Fallback to /bin/sh when using /bin/csh and /bin/tcsh
Delete .vimrc autoreload since it is inconsistent

1) ~/.vimrc is not the only place for Vim configuration, e.g. ~/.vim/vimrc
2) It is the only case where this configuration set uses autocmd
3) This can be often unwanted and suprising behaviour
Move it closer to a possible consensus

This commit primarily drops settings that can be found inappropriate by
users of the plugin. That includes:

+ no wildignore preset (still, wildmenu is still there)
+ no identation presets (no shiftround, tabstop and so on)
+ no preset bindings (drops CTRL+L for disabling hlsearch)

This also adds missing documentation for all options set in modern.vim,
sets them in alphabetical order and uses '' instead of "". Enjoy!