fpspreadsheet: Support for column widths and row heights of xlsx reader. Extend unit tests --> passed. Add "debug with heaptrc" build mode to spreadtestgui (--> there is an unfixed memory leak in fpsfunc).

git-svn-id: http://svn.code.sf.net/p/lazarus-ccr/svn@3418 8e941d3f-bd1b-0410-a28a-d453659cc2b4