Duplicated -X entries with etc-default-template

[muuki88]

My etc-default contains this line

-J-Xmx256m

when I install my debian package and call the script with -d I get the following output

-Xms1024m
-Xmx1024m
-XX:MaxPermSize=256m
-XX:ReservedCodeCacheSize=128m
-Dconfig.file=/usr/share/mukis-application-conf/conf/application.conf
-Xmx256m

According to Stackoverflow this is not a good idea.

[jsuereth]

Yeah, it's super bad. This is an issue with the -mem option. However, I thought we had something to detect -X options and not use the -mem hooks if the user directly specifies something with -J-X....

If not, we should merge this fix back into the native-packager:

https://github.com/sbt/sbt-launcher-package/blob/master/src/universal/bin/sbt-launch-lib.bash#L82-L96

[muuki88]

Even it's not ham-fisted, we have it already in our code:
https://github.com/sbt/sbt-native-packager/blob/master/src/main/resources/com/typesafe/sbt/packager/archetypes/bash-template#L157-L165

But it doesn't work :)

[muuki88]

I think this is the last blocker for our 0.7.0 release. @jsuereth , @aparkinson , @kardapoltsev , any objections?