Consistent license directory for gempa modules

For maintaining consistent SeisComP systems with gempa modules we are now dropping the default support for licenses in @CONFIGDIR@/licenses and only read from @DATADIR@/licenses.

SeisComP in version 4 is distributed under AGPL license and no license files are required any longer. However, gempa modules and plugins typically read their specific license files. The default location of these files is @DATADIR@/licenses ($SEISCOMP_ROOT/share/licenses). Until recently, the license files could also be read from @CONFIGDIR@/licenses ($HOME/.seiscomp/licenses). For maintaining consistent SeisComP systems we are now dropping the default support for licenses in @CONFIGDIR@/licenses and only read from @DATADIR@/licenses. However, we will allow you to change the path to the licenses directory by configuration of the new parameter gempa.licensePath which you can add to your module configuration. Alternatively, use global configuration if your gempa application reads from it - most gempa applications do so.

Steps to take:

1. Check if you have license files in @CONFIGDIR@/licenses and @DATADIR@/licenses, keep only those currently relevant and move them to @DATADIR@/licenses. Alternatively update all your licenses from our package server and place them in @DATADIR@/licenses.
2. Remove the directory @CONFIGDIR@/licenses if existing.

Once the configuration parameter gempa.licensePath is reported in the documentation of your module, you may relocate licenses and adjust gempa.licensePath in your module configuration. We recommend to relocate license files only in exceptional cases and stay with licenses in @DATADIR@/licenses.

Your team of gempa!