The following anomalities were found in policy files parsing:

1) The syntax of the "grant" entry in policy files is:
   grant codebase "SOME-BASE" signedby "ALIASES LIST" {...}

   The PolicyParser class allows multiple codebase &
   signedby clauses in the same grant entry, and disregards all
   but the last ones. It should throw a ParsingException instead.
   The place to catch this condition is in the parseGrantEntry
   method of the PolicyParser class.

2) In the signedBy "ALIASES LIST" clause of the grant entry, if
   a string like the following is supplied: "ALIAS1, ,ALIAS2",
   the grant entry is ignored (which is o.k.) but no ParsingException
   is thrown. It should be thrown, since a string of spaces is not
   a legal alias. What happens instead, is that the string of spaces
   is considered a legal alias, and since no such alias is ever found
   in the keystore - the grant entry is disregarded.

   The signedBy string is parsed in the getCerticiates method of
   the PolicyFile class. This function should check for this
   condition and throw an exception.