Added ability to tell bower to ignore specific packages

Example:
```javascript
{
  "suppliedDependencies": {
    "jquery": true,
    "jquery-regex": "jquery.*"
   }
}
```

If you set the value as true, it'll just check do a straight string equivalency test on the name of the package being installed. If you supply a string, it'll to do a regex test on the package name using that string.

Any packages found are logged out as "skipped."

Related: #927