New weights files: NASNet, DenseNet

Centralizing the storage location of weights files referred to in the keras.applications module.

Add InceptionResNetV2

v0.7

Add inception_resnet_v2

MobileNet

Code contributed by Somshubra Majumdar. Weights ported from tensorflow/models.

Keras 2 API, new Inception V3 weights

v0.5

Update models to V2 API.

Xception model

Add the Xception model with ImageNet weights.

Music tagger model

Add the music tagger CRNN by @keunwoochoi.

InceptionV3, updated ResNet50

Merge branch 'master' of https://github.com/fchollet/deep-learning-mo…

…dels

VGG16, VGG19, and ResNet50

Add code and weights for VGG16, VGG19, and ResNet50.