get WFS default pagesize from GetCapabilities request

[smnorris]

Safer than setting it at 10k - as per bcgov/bcdata#256

[smnorris]

This is the xml in the GetCapabilities response. Not sure how to pull it out from owslib.wfs

<ows:Constraint name="CountDefault">
<ows:NoValues/>
<ows:DefaultValue>10000</ows:DefaultValue>
</ows:Constraint>

[smnorris]

Really not interested in parsing the xml

[smnorris]

Default page size has been reduced to only 500 records, this is now a critical issue.

[smnorris]

500 max features is really small!

To fix:

• dropping the pagesize option from the various commands in the CLI seems reasonable, I never use that anyway and can't see wanting to reduce the size even if the 10k limit is restored
• revert to caching the getcababilities xml, not the list of tables
• parse xml to get the CountDefault

[smnorris]

Might be able to avoid the xml parsing?

owslib does note the constraints, but doesn't seem to hold the values?
https://github.com/geopython/OWSLib/blob/master/owslib/feature/wfs200.py#L171

>>> WFS.operations[2].constraints[1].name
'CountDefault'
>>> WFS.operations[2].constraints[1].values
[]

It does look for values, not sure why they aren't there:
https://github.com/geopython/OWSLib/blob/master/owslib/ows.py#L175

But referencing the constraints by their index in the lists seems like a bad idea.

[smnorris]

fixed with #145