fpspreadsheet: Add financial function PV and PMT to test_formula_func demo.

git-svn-id: http://svn.code.sf.net/p/lazarus-ccr/svn@3285 8e941d3f-bd1b-0410-a28a-d453659cc2b4
fpspreadsheet: Remove unused unit from excel8read project

git-svn-id: http://svn.code.sf.net/p/lazarus-ccr/svn@3286 8e941d3f-bd1b-0410-a28a-d453659cc2b4