enhance error handler for saving file
batch delete docs by an very original way
1.expand js string functions: isEmpty(), isNotEmpty
2.bug fix for  uploading no type file
3.enhance for displaying doc name column
4.change a js file name
enhance RequestMap for distinguish request success and failure
1. bug fix for delete doc
2. bug fix for string isEmpty function
support to create directory
bug fix for button enable/disable issue
enhancement