Tony's comment on output format
Inline helper functions of label
Add option to return number of labels
Add test case for number of labels
add option full_output to hough_circ
Fix 64-bit multipage tiff writing segfault
Merge pull request #507 from zachrahan/freeimage-multipage-64

Fix 64-bit multipage tiff writing segfault
Merge pull request #496 from ahojnnes/label-performance

ENH: Inline helper functions of label and add number of regions as an optional return.
Add multipage TIFF unittest
Merge pull request #508 from zachrahan/freeimage-multipage-64

Add multipage TIFF unittest
Merge pull request #488 from sciunto/minor_docfix

ENH: Allow `hough_circle` to detect circles with centres outside the image.
Fix Emmanuelle Gouillart's name in the contributors list.