Log Message:
update to roundup 0.5.6.  changes:
- fixed templating filter function arguments (sf bug 678911)
- fixed multiselect in searching (sf bug 676874)
- fixed parsing of content-disposition filenames (sf bug 675116)
- added 'h' to roundup-server optarg list (sf bug 674070)
- fixed doc for db.history in anydbm and rdbms_common (sf bug 679221)
- fixed roundup-reminder (sf bug 681042)
- fixed int assumptions about Number values (sf bug 677762)
- clarified licensing
- another attempt to fix cookie misbehaviour - customise cookie name using
  tracker name
- fixed error in indexargs_url (thanks Patrick Ohly)
- fixed getnode (sf bug 684531)
- fixed args to some date templating methods (sf bug 689670)
- fixed database corruption in rdbms property mutation