use iconReadMat.m instead of iconRead.m in tgs_util, used to load .mat icon...

use iconReadMat.m instead of iconRead.m in tgs_util, used to load .mat icon file. Under the compiled version, icon path was bad
Add directory tsg_tools/icons with tool iconRead used to transform .gif and .jpeg to .mat CData  
Add test with version > R2014b using root properties as get(0, 'Units'), that failed with compiler.
if verLessThan('matlab','8.4')
  set(0,'Units','normalized');
  guiLimits = get(0,'ScreenSize');
else
  r = groot;
  r.Units = 'normalized';
  guiLimits = r.ScreenSize;
end