fix ANOVA for sample table

This commit restores our ability to perform the ANOVA analysis on
our sample liver data.  In order to accomplish this, I added a
new attribute to the input element of our analysis XML description
files.  This attribute is called "metadata".  If it is set to false,
then only the "data" portion of the table will be loaded as input
into the analysis.  By default, the entire table is loaded as input,
metadata and all.
update documentation

Include description of the new "metadata" attribute.
add test for ANOVA
fix and test FOLD & KMEANS analyses

Similar to previous commit, get these two analyses working for
the sample liver data again, and add new tests for them.
Merge branch 'table_metadata'

* table_metadata:
  fix and test FOLD & KMEANS analyses
  add test for ANOVA
  update documentation
  fix ANOVA for sample table