Fix for issue #11 Show what's happening when installing front-end packages

@JonAbrams Giving this one last (4th) shot for tonight. Apparently node doesn't like the chaining of .on's. Ran npm test on this one and all good. Hopefully. #11 
I just took a look at this.

The `log` is an object so it is not so nice to print with console.log.
```
{ level: 'action',
  id: 'install',
  message: 'angular#1.2.22',
  data: 
   { endpoint: { name: 'angular', source: 'angular', target: '1.x' },
     canonicalDir: '/Users/mmoller/.cache/bower/packages/ef2188def21eb1bbd1f1792311942a53/1.2.22',
     pkgMeta: 
      { name: 'angular',
        version: '1.2.22',
        main: './angular.js',
        dependencies: {},
        homepage: 'https://github.com/angular/bower-angular',
        _release: '1.2.22',
        _resolution: [Object],
        _source: 'git://github.com/angular/bower-angular.git',
        _target: '1.x' },
     dependencies: {},
     nrDependants: 1 } }
```

But I agree we should not require a deep third-party package.

I think this will be good enough:
```
bowerInstall.on('log', function(log) {
        console.log("Bower:", log.id, log.message);
    });
```

For the included template, this gives this output:
```
mikaelhm$ synth install -f
Bower: resolve git://github.com/angular/bower-angular-route.git#1.x
Bower: resolve git://github.com/angular/bower-angular.git#1.x
Bower: download https://github.com/angular/bower-angular-route/archive/v1.2.22.tar.gz
Bower: download https://github.com/angular/bower-angular/archive/v1.2.22.tar.gz
Bower: extract archive.tar.gz
Bower: invalid-meta angular-route is missing "ignore" entry in bower.json
Bower: resolved git://github.com/angular/bower-angular-route.git#1.2.22
Bower: extract archive.tar.gz
Bower: invalid-meta angular is missing "ignore" entry in bower.json
Bower: resolved git://github.com/angular/bower-angular.git#1.2.22
Bower: install angular-route#1.2.22
Bower: install angular#1.2.22
```