fixed some bugs that "sneaked in" with the latest changes:
fixed some bugs that "sneaked in" with the latest changes:

- when creating new Heap's, be sure to initialize the
  "filename" properly; otherwise, HEAPfree will fail with segfault!

- be sure not the mix-up *h*heap & *t*heap ...

these bug were detected by the following tests:
   tests/Availablility/Tests/02_Modules_plain
   tests/Availablility/Tests/02_Modules_contrib
   tests/BugsViaSourgeforce/Tests/ID.853867
   tests/sigs/Tests/none
(which confirms once again that these tests are useful
 and their results need to be checked seriously...)

(spending yet another Saturday afternoon and night on
 chasing nasty bugs in MonetDB did relieve my bad
 conscience of not working on Queensday though not even
 being Dutch ... ;-)

zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb