This fixes the clang warning
globalsettings_kmail.h:58:5: warning: '~GlobalSettingsBase' overrides a destructor but is not marked 'override' [-Wsuggest-destructor-override]

Summary:
Add a utility function is<Parameter>Immutable to access immutability quickly.
Generated classes uses them internally to avoid code redundance.

Sample:
```
    /**
      Set blocked-by-default
    */
    void setBlockedByDefault( bool v )
    {
      if (v != mBlockedByDefault && !isBlockedByDefaultImmutable() )  {
        mBlockedByDefault = v;
        Q_EMIT blockedByDefaultChanged();
      }
    }

    /**
      Is blocked-by-default Immutable
    */
    bool isBlockedByDefaultImmutable()
    {
      return isImmutable( QStringLiteral( "blockedByDefault" ) );
    }
```

```
    /**
      Set org.kde.ActivityManager.ResourceScoringEnabled
    */
    void setResourceScoringEnabled( bool v )
    {
      if (!isResourceScoringEnabledImmutable() )
        mResourceScoringEnabled = v;
    }

    /**
      Is org.kde.ActivityManager.ResourceScoringEnabled Immutable
    */
    bool isResourceScoringEnabledImmutable()
    {
      return isImmutable( QStringLiteral( "resourceScoringEnabled" ) );
    }
```

Reviewers: ervin, #frameworks, dfaure

Reviewed By: ervin

Subscribers: dfaure, tcanabrava, kde-frameworks-devel

Tags: #frameworks

Differential Revision: https://phabricator.kde.org/D26368

Reviewers: #plasma, #frameworks, dfaure, mart, apol

Reviewed By: apol

Subscribers: kossebau, apol, kde-frameworks-devel

Tags: #frameworks

Differential Revision: https://phabricator.kde.org/D24490

Summary:
In case a kcfg with arg="true" was used and singleton the static
instance method only accepted a QString config name. This made it
impossible to combine a singleton config with an already existing and
open KSharedConfig::Ptr.

With this change an overloaded instance method is added which takes a
KSharedConfig::Ptr as argument. The private ctor, though, only takes a
KSharedConfig::Ptr and the instance method taking a QString argument
uses KSharedConfig::openConfig on the config file name.

The change is source-incompatible in the following situation:
* kcfgfile arg="true"
* Singleton = true
* Inherits is specified

In this situation the previous revision created an instance method with
a QString argument and passed that to the parent constructor. This is
not in accordance with the documentation. Any user of this behavior was
relying on a bug. With this change now the call to the parent
constructor carries a KSharedConfigPtr.

Test Plan:
kconfigcompiler tests still pass and a config with singleton
and arg="true" generates the code as I need it

Reviewers: #frameworks, dfaure, mdawson

Differential Revision: https://phabricator.kde.org/D3690

This reverts commit cd4e6504dfbdface00037625f0cedda511e6d839.

As suggested by Martin on release-team@kde.org, given that it breaks SC.

This reverts commit 71f16741a0288d8587876dcc7dbb33ba8f00546a.

Sorry.

Summary:
In case a kcfg with arg="true" was used and singleton the static
instance method only accepted a QString config name. This made it
impossible to combine a singleton config with an already existing and
open KSharedConfig::Ptr.

With this change an overloaded instance method is added which takes a
KSharedConfig::Ptr as argument. The private ctor, though, only takes a
KSharedConfig::Ptr and the instance method taking a QString argument
uses KSharedConfig::openConfig on the config file name.

This provides full API compatibility and at the same time allows to use
KSharedConfig in addition to the arg name based variant.

Test Plan:
kconfigcompiler tests still pass and a config with singleton
and arg="true" generates the code as I need it

Reviewers: #frameworks

Differential Revision: https://phabricator.kde.org/D3386