Fix SVM::trainAuto (Bug #4464)

commit 5c379aa1
Merge: e800800b 3646967d
Author: Сергей Нужный <snuzhny@stc-spb.ru>
Date:   Wed Apr 8 12:44:46 2015 +0300

    Merge branch 'master' of https://github.com/Nuzhny007/opencv

commit e800800b
Author: Сергей Нужный <snuzhny@stc-spb.ru>
Date:   Wed Apr 8 12:43:38 2015 +0300

    Squashed commit of the following:

    commit 3646967d
    Author: Сергей Нужный <snuzhny@stc-spb.ru>
    Date:   Tue Apr 7 15:48:30 2015 +0300

        Fix bug in SVM::trainAuto

    commit 0c24ccf5
    Author: Сергей Нужный <snuzhny@stc-spb.ru>
    Date:   Tue Apr 7 15:43:59 2015 +0300

        Revert "Fix bug in SVM::trainAuto"

        This reverts commit 225da022.

    commit 225da022
    Author: Сергей Нужный <snuzhny@stc-spb.ru>
    Date:   Tue Apr 7 15:09:47 2015 +0300

        Fix bug in SVM::trainAuto

commit 3646967d
Author: Сергей Нужный <snuzhny@stc-spb.ru>
Date:   Tue Apr 7 15:48:30 2015 +0300

    Fix bug in SVM::trainAuto

commit 0c24ccf5
Author: Сергей Нужный <snuzhny@stc-spb.ru>
Date:   Tue Apr 7 15:43:59 2015 +0300

    Revert "Fix bug in SVM::trainAuto"

    This reverts commit 225da022.

commit 225da022
Author: Сергей Нужный <snuzhny@stc-spb.ru>
Date:   Tue Apr 7 15:09:47 2015 +0300

    Fix bug in SVM::trainAuto

commit 3646967d
Author: Сергей Нужный <snuzhny@stc-spb.ru>
Date:   Tue Apr 7 15:48:30 2015 +0300

    Fix bug in SVM::trainAuto

commit 0c24ccf5
Author: Сергей Нужный <snuzhny@stc-spb.ru>
Date:   Tue Apr 7 15:43:59 2015 +0300

    Revert "Fix bug in SVM::trainAuto"

    This reverts commit 225da022.

commit 225da022
Author: Сергей Нужный <snuzhny@stc-spb.ru>
Date:   Tue Apr 7 15:09:47 2015 +0300

    Fix bug in SVM::trainAuto

2. Algorithm::load/save added (moved from StatModel)
3. copyrights updated; added copyright/licensing info for ffmpeg
4. some warnings from Xcode 6.x are fixed

This reverts commit 225da022.

- added test for loading legacy files
- added version to new written models
- fixed loading of several fields in some models
- added generation of new fields from old data

initial commit; ml has been refactored; it compiles and the tests run well; some other modules, apps and samples do not compile; to be fixed

An SVM train with HOG could export a single vector for HOGDetector.

This should allow many algorithms to take advantage of more parallelization
technologies.

add hack to disable optimization of linear svms; improved precision of optimize_linear_svm; add the relevant test, which however requires some big database (so it's disabled by default)

Added new kernels to documentation

Histogram intersection kernel (accessible by using SVM::INTER in CV namespace as kernel_type)
Exponetial chi2 kernel (accessible by using SVM::CHI2 in CV namespace as kernel_type)

Formulars:
Exp-CHI2
k(x,y) = exp(-gamma * CHI2(x,y))
CHI2(x,y) = 1- 2* SUM_i[(xi-yi)²/(xi+yi)]

Intersec
k(x,y) = SUM_i[min(xi,yi)]