LOB datatype infrastructure support

    Technology preview.
    More changes expected as part of this work before it
    is user ready.
    blueprint lob-support

    This checkin contains basic support for create blob/clob datatypes.
    The feature is disabled by default. Instructions on how to enable are
    listed below.
    New test executor/TEST130 that turns the feature on and tests out the
    functionality.
    New mxlobsrvr process will be started as part of sqstart.
    Create and drop of  tables with LOB columns.
    No support for alter.
    DML support for LOB datatypes.
    Insert, update and deletes. Joins of 2 tables with LOB columns are
    allowed but joins on LOB columns temselves are not allowed.
    Insert-select from one LOB table another not yet supported.
    Link to document from the blueprint will be added shortly.

    To enable and try LOBs:
    On a developer workstation :

    cqd TRAF_BLOB_AS_VARCHAR 'OFF';

    On a cluster after installing the code 2 steps are needed:

    1. cqd TRAF_BLOB_AS_VARCHAR 'OFF';
    2. sudo su hdfs --command "hadoop fs -mkdir /lobs"
       sudo su hdfs --command "hadoop fs -chown -R trafodion:trafodion
    /lobs"

        This checkin includes several merges from the mainline and each of
    the lines below represents one commit to the project branch where this
    work was done. `
        -Turning off LOB code by default. But turning it on in
    executor/TEST130 just to ensure testing the code path.
        -Support for showddl and some syntax for external files and stream.
        -LOB regression test
        -Workaround for dtm issue LP 378167
        -Changes to make append work. Changes to use lob heap.
        -Fix for using system heap for all LOB allocations and handling NULLs.
        -Added workaround for cursor delete issue. LP 1376969
        -Fixes for update.
        -Parser changes for exe_util_lob_extract
        -Pull in lob extract code
        -Adding mxlobsrvr directory

        -Fixed the LOB interface to use  2 new params for cursor fetches. They do
        not overload the LOB Handle and LOB handle length anymore.
        Added a flag to lobGlobals to indetify it's a hive access.
        Cleaned up parser code.

        -LOB support for create,drop,insert,delete,select.

Change-Id: I7c8125696e847b71580b746388632e75741bd347