[ctioga2] Z values can now change the marker size in parametric plots

git-svn-id: svn+ssh://rubyforge.org/var/svn/ctioga2/trunk/ctioga2@513 86c91514-0d3b-42e0-aed1-4dfce116d947
[ctioga2] new tests for the parametric plots

git-svn-id: svn+ssh://rubyforge.org/var/svn/ctioga2/trunk/ctioga2@514 86c91514-0d3b-42e0-aed1-4dfce116d947
[ctioga2] make it possible to make a min/max mapping for the marker size

git-svn-id: svn+ssh://rubyforge.org/var/svn/ctioga2/trunk/ctioga2@515 86c91514-0d3b-42e0-aed1-4dfce116d947
[ctioga2] error bar color now defaults to the marker color

git-svn-id: svn+ssh://rubyforge.org/var/svn/ctioga2/trunk/ctioga2@516 86c91514-0d3b-42e0-aed1-4dfce116d947