Bower plugin

Hi!

I've noticed, that a few folks are using this plugin, so I thought it would be nice to make it available from the original repo.

Here is the description:

Bower is a package manager for the web.
This plugin provides some aliases and completitions for this great tool.

### Aliases

`bi`: installs a package (`bower install`)
`bl`: lists installed packages (`bower list`)
`bs`: searches for packages (`bower search`)

### Completition

It completes the basic commands for bower. It uses the `bower help` command to achieve this, not a burned-in list of commands.
It also provides completition for bower install, uses the output of bower search. It takes a few seconds for the first time (in the session), but then the output of `bower search` is cached, so things then speed up a lot.

### Example

```
# to install jquery for example
bi jq<TAB>
```