fix error v1
Merge branch '3.0'

Conflicts:
	zss/src/org/zkoss/zss/api/model/CellStyle.java
	zss/src/org/zkoss/zss/api/model/impl/CellStyleImpl.java
tunning
#ZSS-224: 
 * fix overflow issue, calculate the width through counting the right
sibling cell.
 * remove unnecessary code.
Merge branch 'origin/3.0'

Conflicts:
	zssapp/src/org/zkoss/zss/app/MainWindowCtrl.java
importer/exporter and zssapp exporter composer issues
finetune spreadsheet editor focus
finetune for zssapp
row height and column width api
zssapp minor fix (not ready yet)
enhnance set font size, fine tune rowheight , column width api
#ZSS-224: fix disappeared right grid line issue even no overflow.
Merge branch 'ZSS-224' into 3.0
update release-note.
finetune api name for zssapp
fine tune zss app to new api (not ready)
fix ZSS-304 hiding columns doesn't work
Merge branch 'origin/3.0'

Conflicts:
	zkdoc/release-note
finetune component event to support book event
upgarde note