Task-number: QTCREATORBUG-1795

Move open project dialog handling into ProjectExplorer and make it
use its list of project file patterns. Same in Checkout wizards.

Task-number: QTCREATORBUG-1759
Reviewed-by: dt

Rename IWizard::Kind --> IWizard::WizardKind, add some logic for which wizard kinds to collapse/expand.

  * Use id() for methods returning a string used to represent
    some type of object.
  * Use displayName() for strings that are meant to be user
    visible.
  * Quieten some warnings while touching the files anyway.
  * Move Factories to their products in the plugins where that
    was not done before.

Reviewed-by: dt

Introduce new QString id() const-API and sort wizards by
[untranslated] category and id. Introduce respective constants.
Rubber-stamped-by: con <qtc-committer@nokia.com>

Remove unused code.

Move GitClient::filterUntrackedFilesOfProject into submit editor.
Make checkout wizards use page lists for greater flexibility.

Task-number: 244831