increase external_id field length to 100 varchar
change gene_accession to gene_accession_id to line up with new field
name in experiment core
Begin to document the statistics method used
Merge branch 'master' of https://github.com/mpi2/PhenotypeArchive

* 'master' of https://github.com/mpi2/PhenotypeArchive:
  added onError="continue" for now
  fixed typo, should be top_level_mp_term not top_level_ma_term
  removed duplicate  <field name="top_level_mp_term" type="string" indexed="true" stored="false" multiValued="true"/>/>
  removed duplicate select_top_level_ma_term
  added missing select_top_level_ma_term for copyfile
  added <copyField source="annotatedHigherLevelMpTermName" dest="top_level_mp_term" /> 	<copyField source="subtype" dest="marker_type" />
  added <copyField source="inferred_selected_top_level_ma_term" dest="selected_top_level_ma_term" />
  added <copyField source="annotatedHigherLevelMaTermName" dest="selected_top_level_ma_term" /> 	<copyField source="annotatedHigherLevelMpTermName" dest="top_level_ma_term" />
  added genes to ma index through images annotated to MA as in images there is manual gene annotation
  added  <copyField source="annotatedHigherLevelMaTermName" dest="selected_top_level_ma_term" />     <copyField source="annotatedHigherLevelMpTermName" dest="top_level_mp_term" />
  added comment for removing ma -> mp mapping
  removed some tests that relate the the heatmap as broken, but this is a work in progress
  heatmap working almost with mp terms
  added new heatmap for idg still some work