set multidim according to chart type
show 'multidim' checkboxes if chart_is_multidim
generate multiple entries for multidim facets
multidim facets depend on facets of same axis
multidim constraints for subsequent facets
all constraint generation happens in save_value
change handling of multiple dimensions in schema
change xy and xyz flags to multidim field
fix bug: don't remove models during iteration
add labels to four_dimensions fixture
parse multidim facets from model
set multidim_common=true for non-multidim facets
'value' facet also needs to be multidim_common
generate y_title only if unit-measure is available
generate x_title only if facet is available
actually, only 'value' is multidim data column
rename instance variable
introduce multidim_value flag for value facet
fix facet ordering
Merge branch 'editor-multidim'