Doc changes from Andreas Schild via transifex

[robe]

This is to accumulate all of Andreas Schild current outstanding changes sent via transifex messaging.

Andreas Schild created an issue for a string in the resource reference_raster.xml.pot 
 
Andreas Schild created an issue for the string: Create a set of raster tiles with <xref linkend="RT_ST_MakeEmptyRaster"/>. Grid dimension is <varname>width</varname> &amp; <varname>height</varname>. Tile dimension is <varname>tilewidth</varname> &amp; <varname>tileheight</varname>. The covered georeferenced area is from upper left corner (<varname>upperleftx</varname>, <varname>upperlefty</varname>) to lower right corner (<varname>upperleftx</varname> <varname>width</varname> * <varname>scalex</varname>, <varname>upperlefty</varname> <varname>height</varname> * <varname>scaley</varname>). 
 
meaning of "upperleftx width"? Minus sign? : "upperleftx - width * scalex" ?