math/saga: 2.2.6 -> 2.2.7

SAGA GIS version 2.2.7 [r2893] is a bug fix release, because a
serious bug in the command line interpreter saga_cmd prevents correct
setting of floating point value parameters.

Some more fixes and features are:

• taking respect for future use of new date parameter
• bug fixes for flip method in grid operation and orientation
• overworked grid system
• bug fix for atan2, which did not work before
• bug fixes for some tool parameter ids
• updated dictionaries and tool interfaces

PR: 209175
Submitted by: Rainer Hurling <rhurlin@gwdg.de> (maintainer)