[WFS] Update WFS docs with info on latest WFS enhancements

[dmorissette]

We need to update the WFS server howto with info on the new features that are
supported in Mapserver 4.1's WFS interface (filters, etc).

If there were any changes in the WFS client then the WFS client should be
updated as well.

[dmorissette]

The 4.2 version of the WFS Server HOWTO doesn't seem to have been updated yet
and still contains inaccurate information. OGC will release its "WFS Cookbook"
with a copy of the out ofdate information in it. That's no good.

For instance, the limitations on lack of support for filters and XML POST
requests are not true any more, so I'll take that out right away.

Assefa, do you have a list of the changes required to the document for v4.2 and
4.3? If we could have that then I could try to update the document myself.

[dmorissette]

The WFS client HOWTO is also very out of date, there is bug 417 about issues in
this document already. We'll also need the necessary information to update the
document.

[assefa]

Here are the changes that I think of :
 * new metadata added at map level :

wfs_namespace_prefix  #used to specify user defined namespace and uri
wfs_namespace_uri     # in GetFeature and DescribeFeature requests

 * FilterEncding support has been added. The follwing capabilities are availble :
    - Spatial Operators : Intersect, DWithIn, BBOX
    - Logical Operatorsn : AND, OR, NOT
    - Comparison Operators : Simple comparison, Like, Between

 * Support of the Get and Post Requests :
  before version 4.2, only Get request were supported. Starting from version
4.2, mapserver supports XML-encoded POST requests. Note also that stating from
mapserver 4.2 all wfs client requests are done using the post method. 

  * Things that should be removed in To-do itmes:

    -  GET request item (Danile already mentionned that)
    -  Filter Encoding (Danile alread mentionned that)
    -  The GetFeature validation :  It validates using the OGC xml validation tool

 If I think of other things, I will reupdate the bug.
 

[jmckenna@…]

updated wfs-server and wfs-client docs:

- new ogc metadata were added in bug#992
- updated wfs-client with metadata-connection params (bug#417)
- link to new filter-encoding doc included in both
- support for get and post mentioned in both
- updated list of limitations in wfs-server

committed to main cvs and branch-4-4