fix some portability issues

- PATH_MAX not defined on the Hurd
- IA64 doesn't need -m64
allow compiling with assert=no
fix memleak
Bestofclass -> GtChain2DimBestofclass; make variable more local.
Litte formatting cosmetics.
Verified that firstinchain is used only for local chaining.
Verify which functions are used for local chaining.
First Version of nd_retrace_allprevious incorporated.
Added attribut storedinreverseorder.
Nondeterministic chaining seems to work.
Fixed remaining bugs in nondeterministic chaining.
Removed unnecessary parts of the assertions.
Fixed splint errors.
allow 'make docs' with cairo=no
update WWW docs
splint-fix commit 245d01deb2ff6
implement asqg writer module
implement output of string graph in asqg format
asqg_writer: use fast tbe decoder
rdj prefilter: add FastQ support (SE)