ignore mouse-scroll if scroll-bar is not present.

fixes http://tracker.ardour.org/view.php?id=5557
improve caching of metric and tick patters

* selectively clear cache (meterbridge, mixer)
* free memory of patterns on clear
switch to WM::Proxy Action management

fixes http://tracker.ardour.org/view.php?id=5584
Update Russian translation
Use a static string variable for dll path.
Making this consistent with all other funtions in this file.
Formatting only.
Lazily load bundled LV2 plugins in LV2PluginInfo::discover()
- Do this instead of finding them in the static ctor of LV2World
- Prevents usage of ARDOUR_DLL_PATH environment variable before
  it is set in main(...)
set the flag true
Housekeeping
move ardour meter globals into dedicated namespace (TODO meter_patters typedef)
simplify meter-type context menu

in preparation for adding more meter-types
add VU and IEC meter DSP (from jmeters)
add new meter-type enums (amend 80aa2574)
Revert new meter types (postponed until after 3.3 release)

This reverts commit ce621d1c8a600853be0020942a9664ccee0ab165.
This reverts commit 80aa2574819e947668092c660d767e25a661c6f1.
Fix typo in osx BETA startup screen
- Step #2 was being skipped in the text
Correcting Indentation Errors
Startup BETA Mac Screen - Pull version number from VERSIONSTRING
Merge branch 'apple' of https://github.com/mfisher31/ardour
add option to disable cairo-RGBA overlays for meters.
tweaks to NO_PLUGIN_STATE logic