Updating the branch to use spatialindex-1.8.0 in line with trunk; this
is necessary to support recent gcc versions.
For some reason the bin/ directory isn't present and this causes the
install of local scripts to fail; adding in a mkdir -p into the scripts:
Makefile.in rule to deal with this. This may cause some conflicts when
merging back into the trunk or merging trunk into this branch, but solves
the immediate problem.