Avoid saving user-specific data in instance scripts

[pun-ky]

Task instanceUp is saving e.g JAVA_EXECUTABLE absolute path in control/\*.\[bat|sh] scripts and  it makes instances not usable directly when extracted externally (outside of GAP usage). 

Consider passing user-specific data to instance scripts using arguments or env vars instead of writing them down to files that could be later a part of instance backups.

Thx @szymon-owczarzak for reporting it!

[szymon-owczarzak]

Or a system variable for the username could be used in JAVA_EXECUTABLE: C:\Users\%Username%\.gradle\jdks\jdk8u275-b01\bin\java.exe

[pun-ky]

How about backup made on Unix but reused on windows? 😁 Nope

[szymon-owczarzak]

for *.sh we could use $HOME/.gradle/jdks... and for *.bat %userprofile%/.gradle/jdks..

[pun-ky]

Distro of Java determined by Gradle could be different for each OS.