Git: Move executeGit into VcsBaseClientImpl

and rename it to vcsExec. Accept a QVariant to set as cookie on the
command instead of a int for the linenumber.

Change-Id: I8240b53e775ac3883f92bdbf7b111abeeeb39426
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/git/gitclient.h

@@ -368,11 +368,6 @@ private:
     void requestReload(const QString &documentId, const QString &source, const QString &title,
                        std::function<DiffEditor::DiffEditorController *(Core::IDocument *)> factory) const;
 
-    VcsBase::VcsCommand *executeGit(const QString &workingDirectory, const QStringList &arguments,
-                                    VcsBase::VcsBaseEditorWidget *editor = 0,
-                                    bool useOutputToWindow = false, unsigned additionalFlags = 0,
-                                    int editorLineNumber = -1);
-
     // determine version as '(major << 16) + (minor << 8) + patch' or 0.
     unsigned synchronousGitVersion(QString *errorMessage = 0) const;