Merge pull request #66 from HaibingShao/ops_kin

Ops kin
adding a safety control before getting _J_2_kin_ast and _J_1_kin_ast.
adding the neckar1D example solved by REDUCT_GIA method.
Merge pull request #67 from HaibingShao/haibing_working

taking the changes of safety protection in REDUCT_GIA