add support to handle double quote nesting

Changed for cases when there is an array of composite types, for example, needing to be tokenized:
(2,"honda     ","April 1, 2008"),(3,mitsubishi,"August 12, 1998"),(4,"nissan    ","5"" tall, and 3"" wide") 

Originally this: 
PGtokenizer token = new PGtokenizer(PGtokenizer.removePara("(2,\"honda     \",\"April 1, 2008\")"),','); 

would be split into 4 tokens with the date split at the comma. Now, if using PGtokenizer on each element the quotes will be taken into account as stated in http://www.postgresql.org/docs/9.3/static/arrays.html: 

"The array output routine will put double quotes around element values if they are empty strings, contain curly braces, delimiter characters, double quotes, backslashes, or white space, or match the word NULL. Double quotes and backslashes embedded in element values will be backslash-escaped. "