corrected bug in features positions after delete

fixed a bug:
_coord_adjust_deletion: test for features overlapping only one end of
the deletion site had incorrect use of Bio::RangeI::contains, which led
to incorrect adjustment of positions ifor features that start at the
start of the deletion site and extend beyond the deletion's end point.
Added a new test case for this situation.
throw exception on negative positions

changed _coord_adjust to check for negative positions, which now lead to
an exception. Previous behaviour was to allow such coordinates but the
resulting adjustments were incorrect because they were treated as
positive numbers
Test that long label qualifiers can be parsed in genbank format.
Quote qualifiers that are so long that they are line wrapped in genbank format.
Fixed bug in move_id_to_bootstrap where supportvalues of 0 where
silently dropped.
update tests for perl 5.18
Return a scalar in scalar context, as per the specifications
Tests for Bio::Taxonomy::get_tree
Fixed POD indentation
Use list context instead of scalar context to include all taxa
Avoid use of an undefined value as an ARRAY reference
Test uses species, not intermediary node
Use a default format for as_string
Adding arbitrary branch length in Bio::DB::Taxonomy::get_tree
Small POD and and error message change
One more test
Fixed redefined variable
Fixed use of uninitialized value $reporttype
Fixed number of tests in t/ClusterIO/SequenceFamily.t
Boolean return status for merge_lineage()