Merge pull request #1 from qbonnard/master

Modernized the use of OpenCv
[samples] Let detector exit when pressing 'q'
Quad: store points as std::vector

This help integration with other libs (chiligeom) that expect a vector of cv::Point_

Removes as well the scNPoint member: a class called 'Quad' is expected
to have 4 points. No need to store that.
Add missing OpenCV libraries at link stage
Revert "Quad: store points as std::vector"

This reverts commit 169887f39458c37d3c6863c415232cb692a85f64.

This commit breaks the API + leads to undesirable performance.

My bad.
[cmake] Include only required OpenCV modules

While here, print out found OpenCV version during configuration
Rename and install 'creator' and 'detector'

To prevent possible collisions, 'creator' and 'detector' are
renamed into 'chilitags-creator' and 'chilitags-detector'.

The CMake options to enable their compilation have been renamed
to 'WITH_DETECTOR' and 'WITH_CREATOR' (to be closer to common CMake
practises).

These 2 applications are now also installed.
Point2f.cross() does not exist in OpenCV 2.3

Compute the cross-product explicitely to support OpenCV 2.3
Merge pull request #3 from chili-epfl/install_samples

Rename and install 'creator' and 'detector'
Merge pull request #4 from chili-epfl/opencv23_compat

Ensure compatibility with OpenCV 2.3