This function will do the range checking and make
sure there is no overlapping or invalid deletion
There can be only one deletion at one offset value
Delete can't overlap with, nor contains, another delete
This method compares two VTD tokens of VTDNav
objects The behavior of this method is like compare the strings
corresponds to i1 and i2, meaning for text or attribute val, entities
will be converted into the corresponding char
New in 2.0 This method compares two VTD tokens of VTDNav
objects The behavior of this method is like compare the strings
corresponds to i1 and i2, meaning for text or attribute val, entities
will be converted into the corresponding char, return 0 if two tokens
are the identical when converted to Unicode String using toString()
respectively