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...
Fix wiki links

Seems to have broken with GitHub's relative link change https://github.com/blog/1395-relative-links-in-markup-files
Merge pull request #263 from benjaminoakes/patch-1

Fix wiki links

Github's new way of handling relative links broke some of the
links in the readme file.
Prevent side effect of wildignore

Certain wildignore values prevented the various logs from being
viewable.

Fixes #249
Generate helptags independently from user settings

The wildignore setting affects the behaviour of the `= shorthand, so
this changeset replaces the last remaining use of such construct with a
call to exec.
Merge branch 'master' of git://github.com/gmarik/vundle