Cherry-pick MR !221 to stripping21-patches branch

Added angle calculator for decay B+ -> K*+ MuMu, accepting both subdecays of the…

See merge request !221 (merged)

(cherry picked from commit c48ae388)

32bc8956 Added angle calculator for decay B+ -> K*+ MuMu, accepting both subdecays of the… 0519ae96 AngleCalculator for Bu2KstarMuMu: use nullptr instead of NULL, output if K+ and… a2027610 Flipped sign of phi for Bminus case

• [2018-01-20 00:08] Validation started with lhcb-stripping21-patches#243

merged

mentioned in commit 073af5bf