qwt_curve_fitter.* split


git-svn-id: svn://svn.code.sf.net/p/qwt/code/trunk@1829 29e17f8d-cf37-471e-a288-72cc03a76eda
QwtBezierSplineCurveFitter2 temporarily added


git-svn-id: svn://svn.code.sf.net/p/qwt/code/trunk@1830 29e17f8d-cf37-471e-a288-72cc03a76eda
QwtBezierCurveFitter simplified


git-svn-id: svn://svn.code.sf.net/p/qwt/code/trunk@1831 29e17f8d-cf37-471e-a288-72cc03a76eda
missing include added


git-svn-id: svn://svn.code.sf.net/p/qwt/code/trunk@1832 29e17f8d-cf37-471e-a288-72cc03a76eda