Automation: AudacityCommand

This is a squash of 50 commits.

This merges the capabilities of BatchCommands and Effects using a new
AudacityCommand class.  AudacityCommand provides one function to specify the
parameters, and then we leverage that one function in automation, whether by chains,
mod-script-pipe or (future) Nyquist.

- Now have AudacityCommand which is using the same mechanism as Effect
- Has configurable parameters
- Has data-entry GUI (built using shuttle GUI)
- Registers with PluginManager.
- Menu commands now provided in chains, and to python batch.
   - Tested with Zoom Toggle.

- ShuttleParams now can set, get, set defaults, validate and specify
the parameters.
- Bugfix: Don't overwrite values with defaults first time out.
- Add DefineParams function for all built-in effects.
- Extend CommandContext to carry output channels for results.

We abuse EffectsManager.  It handles both Effects and
AudacityCommands now.  In time an Effect should become a special case of
AudacityCommand and we'll split and rename the EffectManager class.

- Don't use 'default' as a parameter name.
- Massive renaming for CommandDefinitionInterface
- EffectIdentInterface becomes EffectDefinitionInterface
- EffectAutomationParameters becomes CommandAutomationParameters
- PluginType is now a bit field.

This way we can search for related types at the same time.

- Most old batch commands made into AudacityCommands.
The ones that weren't are for a reason.  They are used by mod-script-pipe
to carry commands and responses across from a non-GUI thread to the GUI
thread.

- Major tidy up of ScreenshotCommand
- Reworking of SelectCommand
- GetPreferenceCommand and SetPreferenceCommand
- GetTrackInfo and SetTrackInfo
- GetInfoCommand
- Help, Open, Save, Import and Export commands.
- Removed obsolete commands ExecMenu, GetProjectInfo and SetProjectInfo
  which are now better handled by other commands.

- JSONify "GetInfo: Commands" output, i.e. commas in the right places.

- General work on better Doxygen.
    - Lyrics -> LyricsPanel
    - Meter -> MeterPanel
- Updated Linux makefile.
- Scripting commands added into Extra menu.
- Distinct names for previously duplicated find-clipping parameters.
- Fixed longstanding error with erroneous status field number which
  previously caused an ASSERT in debug.
- Sensible formatting of numbers in Chains, 0.1 not 0.1000000000137

src/effects/TimeScale.cpp

@@ -104,7 +104,7 @@ wxString EffectTimeScale::ManualPage()
    return wxT("Sliding_Time_Scale_-_Pitch_Shift");
 }
 
-// EffectIdentInterface implementation
+// EffectDefinitionInterface implementation
 
 EffectType EffectTimeScale::GetType()
 {
@@ -112,8 +112,17 @@ EffectType EffectTimeScale::GetType()
 }
 
 // EffectClientInterface implementation
+bool EffectTimeScale::DefineParams( ShuttleParams & S ){
+   S.SHUTTLE_PARAM( m_RatePercentChangeStart,  RatePercentStart );
+   S.SHUTTLE_PARAM( m_RatePercentChangeEnd,    RatePercentEnd );
+   S.SHUTTLE_PARAM( m_PitchHalfStepsStart,     HalfStepsStart );
+   S.SHUTTLE_PARAM( m_PitchHalfStepsEnd,       HalfStepsEnd );
+   S.SHUTTLE_PARAM( m_PitchPercentChangeStart, PitchPercentStart );
+   S.SHUTTLE_PARAM( m_PitchPercentChangeEnd,   PitchPercentEnd );
+   return true;
+}
 
-bool EffectTimeScale::GetAutomationParameters(EffectAutomationParameters & parms)
+bool EffectTimeScale::GetAutomationParameters(CommandAutomationParameters & parms)
 {
    parms.Write(KEY_RatePercentStart, m_RatePercentChangeStart);
    parms.Write(KEY_RatePercentEnd, m_RatePercentChangeEnd);
@@ -125,7 +134,7 @@ bool EffectTimeScale::GetAutomationParameters(EffectAutomationParameters & parms
    return true;
 }
 
-bool EffectTimeScale::SetAutomationParameters(EffectAutomationParameters & parms)
+bool EffectTimeScale::SetAutomationParameters(CommandAutomationParameters & parms)
 {
    ReadAndVerifyDouble(RatePercentStart);
    ReadAndVerifyDouble(RatePercentEnd);