Add support for GloVe vectors

This release offers improved support for replacing the word vectors used by spaCy.

To install Stanford's GloVe vectors, trained on the Common Crawl, just run

    sputnik --name spacy install en_glove_cc_300_1m_vectors

To reduce memory usage and loading time, we've trimmed the vocabulary down to 1m entries.

This release also integrates all the code necessary for German parsing. A German model will be
released shortly. To assist in multi-lingual processing, we've added a load() function. To load the English model with the GloVe vectors:

    spacy.load('en', vectors='en_glove_cc_300_1m_vectors')
