Added alias 'BundleUpdate' for 'BundleInstall!'.

'BundleUpdate' is a more intuitive and explicit command, whereas 'BundleInstall!' isn't.
escape shell commands for windows

inspired by
https://github.com/gmarik/vundle/pull/228 and
https://github.com/gmarik/vundle/pull/172

Vim patch #445 changed shell escaping and introduced incompatabilities for vundle.
Now vundle only escapes joined commands with double quotes on windows when shellxquote is not set to '('.
This workaround closes https://github.com/gmarik/vundle/issues/146 - the mentioned workaround
is no longer needed, but it does not break a vim configurations which contains "set shellxquote=".

DRY shell escaping and modified (hopefully) all relevant places.
Merge pull request #215 from mt3/master

Closes #206: alias `BundleUpdate` to `BundleInstall!`
Escape the repo URI when cloning
Fix link to vim.org in README

Fixes #217
fix Readme formatting

**V**imb**undle** no longer rendering properly...
use place vim bundle on ~/vimfiles for win32 platform
Merge branch 'master' of https://github.com/lihe757/vundle.git
Merge branch 'master' of https://github.com/lihe757/vundle

Conflicts:
	autoload/vundle.vim