Adding atmospherical rendering for misuka (speed of sound, pure tone attenuation)

[tmschnell]

This PR adds atmospherical rendering to misuka. With three new input fields for user:

• propagation medium (string holding parameters like temp, real hum...)
• Speed of sound method (use atmospheric dependent speed or specific user input)
• apply attenuation (will fail run if selected but not matching atmospheric data was given)

Main changes:

• pulling new misuka branch (as discussed with @mberz and @tjueterb)
• adding input fields for new data
• change misuka_interface to use new features

(IR synthesis uses ether user speed of sound or computed one depending on user selection)

[tjueterb]

Let me review the changes you did to misuka.

Once the changes there are final, let's create a tag instead of checking out a branch so we can guarantee consistent behavior over time.