4.2.2.4b (Lisias) for KSP >= 1.2

• Updates the INSTALL.md file to reflect the new deployment model.
  • A new MM/L release wasn't really needed, but since I failed to update the install instructions and there're people using this, I choose to be conservative on the matter.
  • There're no changes on the DLL, so I choose to shove a "b" on the same release number.

Note: files with -122- in the name are meant to be used on KSP 1.2.2.