add handler that allows to export a several tables to excel.
add a flag to GMAP3 that makes map's JavaScript not fail in case of no
Internet connection
make general purpose cell exporter more robust and flexible
fix logic to create table headers.
Merge pull request #245 from reiern70/master

-add handler that allows to export a several tables to excel (POI)
-add a flag to GMAP3 that makes map's JavaScript not fail in case of no internet connection (GMAP3)
-make general purpose cell exporter more robust and flexible (POI)
-fix logic to create table headers (POI)