[BUGFIX] Raise max. memory for Osmosis in Windows to 3GB (#171)

* max. memory for Osmosis in Windows to 3GB

- reverts the deletion of this line in #42
- in context to https://help.openstreetmap.org/questions/21642/osmosis-outofmemory-java-heap-space

* Bump to version 3.1.1a0

only in setup.cfg

wahoomc/tooling_win/Osmosis/bin/osmosis.bat

@@ -1,5 +1,8 @@
 @ECHO OFF
 
+REM # set the max. memory to be used to 3GB
+set JAVACMD_OPTIONS=""-server -Xmx3G""
+
 REM This is an equivalent Windows batch file to complement the unix shell script
 REM Corresponding lines from the shell script are printed before the matching batch file commands