[LAA] [ANN] meters.lv2 v0.5.1

Hi, In the wake of overhauling Ardour's bar-graph meters, I've taken the time to implement corresponding needle-style meters and more. meters.lv2 features 10 needle-style meters. Mono and stereo variants of DIN, Nordic, EBU, BBC and VU types (which are based on jmeters by Fons Adriaensen). Additionally it includes a Stereo Phase Correlation Meter (needle Display), an EBU-R128 Meter (also based on Fons' implementation) with Histogram and History display, a Digital True-Peak Meter (4x Oversampling, using zita-resampler), a Stereo Phase Scope (Goniometer) and a 31 Band Spectrum-Analyzer. Source-code, info and screenshots can be found at https://github.com/x42/meters.lv2 They have been tested in various environments and fine-tuned to match their corresponding real hardware type by Chris Goddard and Axel Müller. Currently the plugins come in Gtk2 (LV2 GtkUI) and openGL (LV2 #external-ui) variants. Both versions are installed in parallel. The main reason for this is portability and compatibility. Yet the GTK variant UI does run in the host's GUI-thread and may slow down UI response (in particular the goniometer). The openGL versions of the plugins do not have this issue, but require very recent versions of libcairo, libpixman and libpango which are thread-safe. Please see the README included with the source. Caveat: Note that the plugins use the LV2 idle-interface (lv2 >= 1.4.2) The plugin-host must to be compiled with 1.4.2 or a later version of the LV2 SDK. It also must support the http://lv2plug.in/ns/ext/resize-port/ extension. At the time of writing Ardour 3.4 and jalv.gtk from SVN >= 5129 do fulfill these criteria. as always, any feedback is welcome. robin