Fixed an issue of error logging about getRowProperties/getCellProperties/getColumnProperties functions. (Gecko 22/Firefox 22)
File size calculation now looks into sub-directories. Fixed an issue that unreadable files (possibility due to improper file name) causes calculation to freeze.
Continuous special chars in file names now are processed into equal number of alternative chars on capturing a web page.
Truncates very long file names to prevent possible problems.

- Adds ".dat" to files with unknown extension.
- Fixed a small inaccuracy of ScrapBookUtils.crop function.
Fixed a small issue that recapture may give an error log message.
Allows most non-ASCII characters to be the filename on capturing.
Fixed an issue that frames without src setting cannot be correctly captured.

- Also fixed a potential possibility to recapture same iframes
- Optimized getUniqueFileName function