LHCbMath: improve current functionality + add new qmtest
! 2016-12-18 - Vanya Belyaev
- add Gauss-Lobatto interpolation
- improve a bit existing constructors for Bernstein
- add (and extend) qmtest for new interpolation functions (for MR !460 (merged))
! 2016-12-18 - Vanya Belyaev