spark-defaults.conf: set io.compression.codec to LZF

snappyjava has problems loading its native library, so work around it
for now.

Signed-off-by: Colin Patrick McCabe <cmccabe@cloudera.com>
spark-env.sh: get native libraries working for the spark driver

Get native libraries working for the spark driver by setting
SPARK_SUBMIT_LIBRARY_PATH, SPARK_SUBMIT_CLASSPATH.

Signed-off-by: Colin Patrick McCabe <cmccabe@cloudera.com>
sync.sh: sync ~/extra-native

A place to put extra native libraries, like for snappyjava.  Hasn't
quite solved the snappyjava problem yet, though.

Signed-off-by: Colin Patrick McCabe <cmccabe@cloudera.com>
comment out tachyon launching stuff.

Signed-off-by: Colin Patrick McCabe <cmccabe@cloudera.com>