ACCUMULO-1867 use the correct file system when reading the indexes of existing files
ACCUMULO-1884 Fix NativeMap Makefile for OS X

The NativeMap Makefile was originally updated for recent OS X versions
under ACCUMULO-1819, but when the file moved for 1.6.x, the changes
were not included.

Signed-off-by: Eric Newton <eric.newton@gmail.com>
ACCUMULO-1839 Fix ACCUMULO_CONF_DIR usage in Accumulo.java

The lookup of auditLog.xml in Accumulo.java was still looking in
$ACCUMULO_HOME/conf instead of $ACCUMULO_CONF_DIR.

Signed-off-by: Eric Newton <eric.newton@gmail.com>