improvment

Just like in comment by Roel Decoene (on 15 May 2013)
There was lack of functionality that manifest itself, if a page had a link to another page in the same space. After copy to second space, the link is set to confluence/pages/createpage.action?spaceKey=TARGETSPACE&title=orginaltitle&linkCreation=true&fromPageId=parentPageId - so it is chaged to create page in target space. Link should be preserved.
Added Polish translation
Minor refactoring so it would be easier to read and change (I did extracted some constants)