Add r.buffer.lowmem algorithm (and secure r.buffer parameters)

Author: Médéric RIBREUX

python/plugins/processing/algs/grass7/description/r.buffer.lowmem.txt

@@ -0,0 +1,8 @@
+r.buffer.lowmem
+Creates a raster map layer showing buffer zones surrounding cells that contain non-NULL category values (low-memory alternative).
+Raster (r.*)
+ParameterRaster|input|Input raster layer|False
+ParameterString|distances|Distance zone(s) (e.g. 100,200,300)|None|False|False
+ParameterSelection|units|Units of distance|meters;kilometers;feet;miles;nautmiles|False
+ParameterBoolean|-z|Ignore zero (0) data cells instead of NULL cells|False
+OutputRaster|output|Buffer

python/plugins/processing/algs/grass7/description/r.buffer.txt

@@ -2,7 +2,7 @@ r.buffer
 Creates a raster map layer showing buffer zones surrounding cells that contain non-NULL category values.
 Raster (r.*)
 ParameterRaster|input|Input raster layer|False
-ParameterString|distances|Distance zone(s) (e.g. 100,200,300)|
-ParameterSelection|units|Units of distance|meters;kilometers;feet;miles;nautmiles
+ParameterString|distances|Distance zone(s) (e.g. 100,200,300)|None|False|False
+ParameterSelection|units|Units of distance|meters;kilometers;feet;miles;nautmiles|False
 ParameterBoolean|-z|Ignore zero (0) data cells instead of NULL cells|False
 OutputRaster|output|Buffer