Logging improvements

Logging improvements

[Dan Mihai]

1. Define OC_LOG_PRIVATE_DATA bit that can be added to any of the
   DEBUG, INFO, WARNING, ERROR, or FATAL log levels.

2. Don't log OC_LOG_PRIVATE_DATA messages unless they have been enabled
   explicitly, by calling OCSetLogLevel.

3. Use a single OC_LOG_LEVEL instead of the old SET_LOG_INFO,
   SET_LOG_ERROR, SET_LOG_WARNING and SET_LOG_FATAL macros.

4. Always honor the value of g_level - e.g., don't log WARNING messages
   when g_level == ERROR.

5. Windows: add support for specifying the value of LOG_LEVEL in run.bat.

.

[Philippe Coval]

Ported from master to 1.3-rel

Change-Id: I85f6e7a8cb9798708344250ba2cbb278a0e6e7f6
Signed-off-by: Dan Mihai <Daniel.Mihai@microsoft.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/18279
Tested-by: jenkins-iotivity <jenkins@iotivity.org>
Bug: https://jira.iotivity.org/browse/IOT-2453
Signed-off-by: Philippe Coval <philippe.coval@osg.samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/21149