LSP Plugins bugfix release 1.0.23

New release 1.0.23 available. Mostly it's a bug-fix release.

• Fixed buffer overflow in Slap-back Delay plugin series happening with frame size larger than 512 samples.
• Updated expression language for the UI: added literal expressions that are more friendly with XML syntax.
• DSP core functions re-engineering and DSP core interface refactoring.
• Covered many of SSE DSP functions with unit tests.