Propagate NETBEANS_USERDIR environment variable

[jtulach]

• this is the "Windows part" of Make sure netbeans in embedded terminal means itself netbeans#8756
• TBD: it updates the netbeans*.exe launcher to behave the same as Unix one
• first of all it makes the mvn install fail when the C++ compilation fails

[neilcsmith-net]

This repo is out of date and needs archiving. Everything is back in the main repo.