integrate mantissa with Apache commons-math

package org.spaceroots.mantissa.quadrature :

  replace the samplers/iterators by a step handler
  similar to the ones used for ODE.

package org.spaceroots.mantissa.ode :

  add a variational equations integration feature

  replace Shampine dense output by Owren/Zennaro
  formula which requires two additional function
  evaluations but is of 5th order (same order as the
  integrator itself)

package org.spaceroots.mantissa.tabulation

  create the package
