Fix doc.
Layers not always defined.
To fix #356.
Merge pull request #357 from camptocamp/layers-not-defind

Layers not always defined.
Add encodeExternalLayer especially to don't use native angle on external layers.
Swisstopo don't support it.
A fix for non internal WMS layers (like WMTS).
Typo.
Merge pull request #365 from camptocamp/external-wms

2 bugfix reporte par Cartoriviera
Merge branch '1.3'

Conflicts:
	core/src/script/CGXP/plugins/FeaturesWindow.js
    changes => core/src/script/CGXP/plugins/FeaturesResult.js