use global service and version constants
add extension constant to support swes:extensions
add URI for OM_SWEArrayObservation
add todo
add support for extensions
add support for OM_SWEArrayObservation in SOS 2.0 POX request builder
use default constant SERVICE
Replace all deprecated *SERVICE* and *VERSION* references with global SERVICE and VERSION constant.
support extensions
add OM_SWEArrayObservation constants
add support for observation type SweArrayObservation
Add processing of extension parameter
Add support of parsing TimePeriods without resolution by updating PERIOD_PATTERN and TimePeriod(String) constructor
Add QNames required for SweArrayObservation creation
add SweArrayObservation specific ObservationParameters subclass requiring XmlString as observation value.
Merge pull request #24 from EHJ-52n/feature/array-observation

Feature/OM_SWEArrayObservation
Better ITime creation without control by exception
Refactored TimePosition(String) contructor
Rename exception variable
Merge pull request #25 from EHJ-52n/feature/time-constructors

Feature/time constructors