Fix for issue #132 on github
Fix for issue #132 on github

- MultiDim now recreates the HDU list if the plugin is closed and then reopened
  on the same image

sosey/ginga,Cadair/ginga,rajul/ginga,rupak0577/ginga,pllim/ginga,Cadair/ginga,naojsoft/ginga,rajul/ginga,ejeschke/ginga,Cadair/ginga,pllim/ginga,naojsoft/ginga,ejeschke/ginga,eteq/ginga,rupak0577/ginga,stscieisenhamer/ginga,rupak0577/ginga,ejeschke/ginga,eteq/ginga,stscieisenhamer/ginga,sosey/ginga,eteq/ginga,rajul/ginga,pllim/ginga,stscieisenhamer/ginga,naojsoft/ginga,sosey/ginga