mzuther updates K-Meter to v2.2.0 for Windows and Linux

mzuther has updated K-Meter to v2.2.0.

Changes:

• almost complete rewrite.
• should run faster and break less things.
• support for skins.
• full re-validation.
• enabled WASAPI on Windows.
• moved DLLs, skins and documentation to subdirectory "kmeter".
• updated libraries and documentation.