SDMXheader modifications
update DESCRIPTION
master #3 improve performance for concept names parsing
master #3 increase performance (x4-5) of serie parsing
update DESCRIPTION
master #4 fix version.SDMXSchema
master #5 modify type.SDMXType method
master #5 update SDMXType S4 class
master #2 improve SDMXHeader
master #5 fix readSDMX
master #6 fix namespaces handling for as.data.Frame.SDMXDataSet
update DESCRIPTION
master #2 add parsing of extracted date
master #2 adding more object validation rules
master #2 fix Header dates parsing & adding Reporting Dates parsing
master #7 set-up unit tests
milestone version 0.2
Merge pull request #1 from opensdmx/master

merge to upstream