new packages: libspatialite 4.2.0, spatialite-tools, fix libfreexl pkg-config

I have managed to compile spatialite executables (spatial-extended sqlite), but some patching was done.
Could you have a look? (I'll comment the problematic places of code)
This was the most hard to fix.  ./configure decides to use wrong ``-ldl`` compiler flag, there is ``-ldl`` in src/Makefile.am 
Should we patch .am instead?