#2020 extractExecutableFromJar now makes the target directory if necessa...

...ry

Closes #2020
It doesn't appear to be the case to me that the directory doesn't exist. More importantly, if it doesn't, this will fail in the same way the initial directory creation failed. See https://github.com/getlantern/lantern/blob/2020/src/main/java/org/lantern/LanternClientConstants.java#L114