pattern.en.parser.tree: replace xml.dom.minidom with xml.etree.cElementTree
import Tree from parser.tree (Text alias)
parser.tree: replace xml.dom.minidom with xml.etree
pattern.en.parser.sentiment: use cElemenTree instead of minidom (faster)
pattern.en.parser.tree fix small XML bug
pattern.nl import Tree
update pattern.vector examples
minor fix for $()
pattern.db raise csv.field_size_limit
pattern.vector multilingual stopwords
pattern.vector libsvm 3.17
update pattern.vector unit tests
pattern.vector major update

The pattern.vector module has been refactored.
The online documentation is therefore out-of-date.

Fixes:
- Better source code comments
- Multilingual stopwords for count() and Document()
- Corpus was renamed to Model()
	=> model = bag-of-words representation of a corpus
- Functions such as tfidf(), cos(), centroid() can now take dicts and Vectors
- Classifier.classify(discrete=False) yields probabilities
- Classifier.confusion_matrix() computes multi-class matrix
- Classifier.test() uses macro-averaging
- Classifier.auc() area under ROC-curve (experimental)
- Big improvements for Naive Bayes
- Small improvements for KNN
- SVM should now work on Windows 64-bit