Add annotators

Depends on bob.bio.base!131 (merged) and bob.extension!67 (merged)

bob/bio/face/annotator/Base.py

+import bob.bio.base.annotator
+import bob.bio.face.preprocessor  # import for documentation
+
+
+class Base(bob.bio.base.annotator.Annotator):
+    """Base class for all face annotators"""
+
+    def __init__(self, **kwargs):
+        super(Base, self).__init__(**kwargs)
+
+    def annotate(self, sample, **kwargs):
+        """Annotates an image and returns annotations in a dictionary. All
+        annotator should return at least the ``topleft`` and ``bottomright``
+        coordinates. Some currently known annotation points such as ``reye``
+        and ``leye`` are formalized in
+        :any:`bob.bio.face.preprocessor.FaceCrop`.
+
+        Parameters
+        ----------
+        sample : numpy.ndarray
+            The image should be a Bob format (#Channels, Height, Width) RGB
+            image.
+        **kwargs
+            The extra arguments that may be passed.
+        """
+        raise NotImplementedError()