Refactored empty_tag output to closer match Excel's.
chart/test_write_a_latin.rb added.
regression/test_chart_font01 .. 06 added.
work on chart font support. all test pass.
regression/test_escape04.rb added and pass
tests for 0.54 added.
tests for 0.54 pass!
examples/chart_radar.rb added.
examples/chart_secondary_axis.rb : some change
chart.rb : modify documents.
version changed to 0.54.0, add recent change document in Readme.rdoc.