Need consistent behavior between netldi and (linked) topaz login with regards to PWD

[dalehenrich]

see http://forum.world.st/Out-of-memory-crashed-writing-CSV-to-gemstone-directory-tc4934076.html.

Upshot is that both startNetldi and startTopaz should cd to $GS_HOME/server/stones/<stone-name>/logs before launching topaz/netldi executables ... this should give consistent behavior for log files (CSV files in particular) as well as FileDirectory default which uses $PWD and $PWD is fixed by starting location of the topaz/netldi executables.