Support for multiple access points per SA.

Now the STORM_{SA}_ACCESSPOINT variable supports
multiple values. Additional values are used to
create multiple mapping rules for a certain storage area.

No control is done on the ACCESSPOINT values.
Bumped version number to 4.3.5
Updated changelog
Merge pull request #3 from italiangrid/fix/STOR-506

Fix/stor 506
Fix for https://issues.infn.it/jira/browse/STOR-504
Fix for https://issues.infn.it/jira/browse/STOR-560
Fix for https://issues.infn.it/jira/browse/STOR-561
Merge pull request #4 from italiangrid/fix/STOR-504

Fix for https://issues.infn.it/jira/browse/STOR-504
Merge pull request #5 from italiangrid/fix/STOR-560

Fix for https://issues.infn.it/jira/browse/STOR-560
Merge pull request #6 from italiangrid/fix/STOR-561

Fix/stor 561
Merge pull request #7 from italiangrid/develop

Update master to 4.3.5 release