Check for non-null analyte

Check for non-null analyte value in table before accumulating the row in
getSamples().
Rename samplePointId column

samplePointId column name change from "SamplePoint_ID" to
"SamplePointID".
Find chemistry sample info guids

Major and minor chemistry records need both SamplePointID and SamplePtID
values; the SamplePtID values are GUIDs that can be found given a
SamplePointID from the chemistry sample info table. Since the chemistry
reports only provide the SamplePointID, the SamplePtID must determined
before inserting a new record.
Change version to 0.6.0