Windows: Handle -javamaxmem when starting via BAT

[kleinj]

On Windows, the value for the Java maximum heap size is hardcoded in the BAT batch startup scripts, i.e., any -javamaxmem parameter is ignored.

It would be nice to be able to handle this parameter (and -javastack of PR #81), similar to how it's done on MacOS or Linux, but without adding additional dependencies to scripting languages etc not shipped by default on Windows. I.e., when starting via cygwin, the bash startup scripts handle this fine, but the "pure Windows" solution does not.

I see two options:

• Handle the parameters in a script; are Powershell scripts powerful enough to do something like this?
• Provide a small launcher binary (C++?) that just handles this limited argument parsing and then execs Java with the appropriate parameters.

Other options?

I have only very limited Windows scripting experience, perhaps there's someone who'd like to take a stab?