#3 aspell plugin not robust when no dictionaries available

[Matthew Firth]

1/ The code in 'jaspell.cpp' returns random jibberish
if no dictionaries are available. The attached patch
ensures the return buffer is initialised to empty so
this doesn't happen.

2/ The java code in registerDictionaries() should also
handle this a little better (i.e. it shouldn't try and
split an empty string, because it will return an array
with one empty string... which is not good either!).
The attached patch file puts a simple if() around that.

[Matthew Firth]

Patch to correct the above