cui: clean up gradient parts of the background tab page
cui: clean up gradient parts of the background tab page

I forgot to clean this up when cherry-picking
6e61ecd09679a66060f932835622821d39e92f01 (Merge back branch
alg_writerframes to trunk, 2014-03-19).

Change-Id: I531dea63d3b62d16f11d414758012432bb4b2503

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core