Use WMS 1.3 throughout qgis-web-client

Fix issue with reverse axis order that some projections have in WMS 1.3
compared to WMS 1.1. The projection of the client must match the
projection of the QGIS project.
Merge pull request #36 from bstroebl/ensureWMS13_2

Use WMS 1.3 throughout qgis-web-client