[FEATURE][QGIS-Server] Add Web Coverage Service support : funded Ifremer

QGIS-Server already supports standards : Web Map Service (WMS version 1.3.0
and 1.1.1) and Web Feature Service (WFS version 1.0.0) and Web Feature
Service with Transaction (WFS-T).
The French Research Institute, Ifremer, would like that QGIS-Server supports
all the OGC standards.
We (3Liz) are implementing the Web Coverage Service (WCS version 1.0.0)
support in QGIS-Server.
[TRANSUP] Hindi by Harish

Signed-off-by: Werner Macho <werner.macho@gmail.com>
always bundle QtDbus, just in case
[FEATURE] fill ring digitinzing tool
Used to cut holes in polygons and automatically fill them with new
features. Attributes taken from parent feature. Feature form opens
by default. Hold Ctrl key to suppress it.