COMSOL interface & combined wave/GA simulation

Changes

• Introducing classes that represent input data for sound field simulations
  • itaSource
  • itaReceiver
  • itaMaterial
• Introducing Comsol interface
  • has a set of classes to represent a Comsol model tree
  • allows to apply changes to a Comsol model that are specific for acoustic simulations
  • works with input data classes mentioned above
  • Also allows to
    • start simulations
    • read/import results in ita formats
    • ...
• Introduced new functions in Kernel/DSP
  • ita_interpolate_spk_result: Interpolates an itaResult in the frequency domain
  • ita_result2audio_spk: Converts an itaResult to itaAudio using an interpolation in the frequency domain
• Introduced classes for 3D model visualization
  • AC3D
  • Comsol models
• Raven
  • added function to set Material path
  • bugfix with paths using Mac