Use URLS as defined in GetCaps for CSW operations.  #154

Changes the OperationsMetadata objects in ows.py to allow for multiple
urls of the same type (ie. POST/XML and POST/SOAP).
Use utf-8 encoding in CSW requests.
Fix 'id' parameter in CSW's GetRecordById
Merge pull request #156 from kwilcox/master

Use URLS as defined in GetCaps for CSW operations.  #154
Docstrings for buildTileRequest and gettile.

Also includes PEP 8 changes for those two methods.