Build warning fixes.
Merge pull request #770 from asmorkalov:winrt
changed surfFeaturesFinder::find() to allow CV_8UC1 type images 

http://code.opencv.org/issues/2926
some typo
Feature description tutorials made in sync with sample code

sample code : https://github.com/Itseez/opencv/blob/master/samples/cpp/tutorial_code/features2D/SURF_descriptor.cpp

Bug #2888
another update
fix all redefine build errors on some Intel OCL
copying '.classpath' and '.project' to build dir, useful for opening in eclipse
test for the issue #2901
fix for #2901 (en exception was raised when getting empty MatOfDMatch)
Workaround hanging of ocl module when ocl API in not really used
Merge pull request #772 from gpsinghsandhu:featureDescriptionTutorials
Waning fixes for Android samples
Merge pull request #769 from apavlenko:fix_2901
Merge pull request #771 from gpsinghsandhu:surfFeatureFinder
Merge pull request #775 from bitwangyaoyao:2.4_fixerr
Merge pull request #777 from taka-no-me:ocl_win_hang
Merge pull request #778 from asmorkalov:android_wanr_fix