when writing table definition, set things up so long variable length columns are...

when writing table definition, set things up so long variable length columns are written after normal variable length columns.  this makes it more likely that all the data can be written sucessfully because long var columns can be written in separate data pages (fix bug [1675522]);  tweak row writing to account for deleted columns

git-svn-id: https://svn.code.sf.net/p/jackcess/code/jackcess/trunk@143 f203690c-595d-4dc9-a70b-905162fa7fd2