Added more automated tests
Added more automated tests

 * Made the "write arbitrary data" tests use smaller
   files to make the test script faster.
 * Added test numbers to text folds.
 * Verify that written data persists when remounted.
 * Verify that garbage collection of unused data blocks works.
 * Verify that garbage collection of interned path segments works.

xolox/dedupfs,xolox/dedupfs,xolox/dedupfs