support for viewParams in WFS GetFeature POST requests
use KVP parser for viewParams in POST requests
support for viewParams in GetFeature POST requests.  ViewParams updated in bindings
Merge remote-tracking branch 'upstream/master' into viewparams_post_support
Merge pull request #195 from GeoffWilliams/viewparams_post_support

support for viewParams in WFS GetFeature POST requests