Expanded configuration format.

It is now possible to create a configuration for installing dependencies in different directories.

for example in my project i create next bower.json

"install": {
    "path": {
      "jasmine": "tests/libs/jasmine",      
      "all": "src/libs"
    },
    "sources": {
      "jasmine": [
        "bower_components/jasmine/lib/jasmine-core.js"
      ]
    }
  },
  "dependencies": {
    "jasmine": "git://github.com/pivotal/jasmine.git#~2.0.1",
    "backbone-min": "http://backbonejs.org/backbone-min.js",
    "jquery": "1.7.0"
  } 

after that backbone-min and jquery were installed in src/libs
and jasmine was installed in tests/libs/jasmine