IMPALA-3737: Local filesystem build failed loading custom schemas
IMPALA-3737: Local filesystem build failed loading custom schemas

When a LOCATION that does not have the scheme specified is used,
the default FS is used as the filesystem scheme.
The default FS is set as 'file:/tmp' for localFS runs, however the
Hadoop library seems to ignore the '/tmp' part of the defaultFS for
locations without schemes and just uses 'file:'.
So the test warehouse is in: 'file:/tmp/test-warehouse'
However, the scripts access '/test-warehouse' without the scheme which
hadoop translates to: 'file:/test-warehouse' which does not exist.

This change disables metadata loading on local filesystem if there is
a schema change detected just as it is done in S3 and Isilon too.

Change-Id: Ie404079aeb2f837ac8b03244b2019e2c8ee9f221
Reviewed-on: http://gerrit.cloudera.org:8080/3384
Reviewed-by: Sailesh Mukil <a0dfbcae8e92bb4f48772d8c6743e175570f6f74@cloudera.com>
Tested-by: Sailesh Mukil <a0dfbcae8e92bb4f48772d8c6743e175570f6f74@cloudera.com>

cloudera/Impala,cloudera/Impala,cloudera/Impala,michaelhkw/incubator-impala,michaelhkw/incubator-impala,cloudera/Impala,michaelhkw/incubator-impala,michaelhkw/incubator-impala,cloudera/Impala,michaelhkw/incubator-impala,cloudera/Impala,michaelhkw/incubator-impala,michaelhkw/incubator-impala,cloudera/Impala