GetFeatureInfo format list in GetCapabilities not respected

[landryb]

Same issue as #301 for GetFeatureInfo, whatever the formats proposed by the server mapstore assumes text/html and application/json are available.

by default mapserver has:

<GetFeatureInfo>
<Format>text/plain</Format>
<Format>application/vnd.ogc.gml</Format>

sure, i can add formats to that list by properly configuring mapserver, but only the formats supported by the server should be listed in the featureinfo layer dialog. Sure, its probably the default that's supported by geoserver, but still some interoperability tests would be nice..

[landryb]

for this issue, the goal is to prevent MS2 to do a GFI query on a server that doesnt support what MS2 expects (eg application/json or text/html depending on the formats) or only lists to the end-user the available formats.

I'm able to crash (Oops, something has gone wrong..) ms2 by selecting text/plain format for GFI on a mapproxy server which doesn't support this format (and replies with json)

on the same layer, using text/html for INFO_FORMAT parameter gets json,and ms2 bails out with There is no information available for this point but at least doesnt crash. A nicer error message would be much better for the end-user...