Updates for #11072022

[Daniel E.]

From a conversation with FlightStream Devs.

- solver "farfield layers" in advanced settings. remnant of agglomerated mesh. 3 is default. really dense meshes can use up to 5. 1 is no agglomeration.
- improvements in speed and memory allocation
- updates to GUI
- New "Flow Separation" option broken out. Default model is "Boundary Layer". Xfoil type BL seperation. "Stratford" sepeartion is not based on BL, only on invsicid flow field; is semi-empirical.  The real difference is in what happens after separation. "Boundary Layer" is reccomended to use. These would not work with bulk separated flow, e.g., flat plate at 90deg. Would likely use Stratfod for VTOL in vertical climb.
- Can now add Plots at anytime in the solution process. e.g., after initializaiton, mid-way through solve.
- New Custom Motion features. Can now specify velocity-time or position-time. Position-time file: [Time, x, y, z, thetax, thetay, thetaz] about which ever chosen axis. Good for
  cyclic-pitch rotor case.
- Truncate Unsteady Wake. Previously, wake was not truncated. This is preferred method for rotors/propellers. But for wings, you can now truncate the unsteady wake.
   Also, for solutions were wake is being translated away.
- "Unsteady Pressures and Kutta terms".  With oscillating wings or impulsive simulations,  unsteady/transient effects which affect solution.
   For cases were steady-state is reached, leave this off.
- Initialization scheme for unsteady cases has been updated. Only part of the velocity-induction matrix is reinitialized. Affects compute time for unsteady cases.
- Probe points can now be edited live. Spreadsheet can now be loaded live. Can also export spreadsheet.
- New Feature: Line Survey. 3D line in space can be used to extract volume flow parameters. E.g., the downwash of a wing.
- Bug fixed in CAD to prevent crashes.
- OpenVSP Best Practices in User Manual.
- Dedicated pages in User Manual for S&C and acoustic scripting.
- Improvement in User Manual for CCS file.