Merge pull request #62 from jerrywell/3.6

ZSS-832: Support hide sheet
ZSS-806: Should NOT show Hidden sheet. Automatically solved when done ZSS-832.
remove generic type for solving build process error.
ZSS-843 close book causes NPE
ZSS-835 if validation type is "any", its Input message will be lost when exporting
ZSS-831 incorrect clipping at page junction when export to pdf
ZSS-845 Support auto update for Cells refer other cells via INDIRECT() function
ZSS-834 Spreadsheet cannot understand data validation which refers to named range whose name comes from formula
fine tune ZSS-835 testcase
fine tune ZSS-834 testcase
ZSS-837 Delete a data validation on a cell doesn't remove browser's dropdown list
ZSS-809 DataValidation does not handle literal list (comma seperated list) correctly.
ZSS-697 Enhance the Chart engine
ZSS-833 Formula in validation's formula field should follow the relative reference rule.
Merge pull request #63 from jerrywell/zss697

ZSS-697 Enhance the Chart engine
ZSS-846 Support clearClientCache to avoid bloated client in some cases.
ZSS-846 Support clearClientCache to avoid bloated client in some cases.
Redo ZSS-814
Fine tune ZSS-846
ZSS-848 Support comment set/get Range APIs