Add QGIS_PROJECT_FILE environement option

To be able to configure the project file in apache configuration
like:
SetEnv QGIS_PROJECT_FILE  <path to project file>.qgs
More general string value.

This option is used for GetFeature and GetfeatureInfo
And for WKT and GML format
Run scripts/update_ts_files.sh
Add French translation
[processing] add points displacement algorithm
[processing] update points displacement alg to new ParameterVector syntax
[processing] add zonal statistics algorithm
[processing] add Points from polygons algorithm
[processing] add Points from lines algorithm (still needs some improvements)
fix rebase conflicts
[processing] add Points from vector algorithm
[processing] add Extract raster values to CSV algorithm
[processing] add Extract raster values to shapefile algorithm
[processing] add two Extract values models (for CSV and shape)
[Plugin Installer] Better error handling for parsing metadata
Allow rotation +-360 degrees in ellipse marker widget
Merge pull request #887 from sbrunner/environ_mapfile

Add QGIS_PROJECT_FILE environement option
Merge pull request #889 from sbrunner/string

More general string value. …
fix retrieval of PYTHON_SITE_PACKAGES_DIR - broke debian builds
Fix crash in rule paste