there are two parts to this patch

1.  	remove all the character-set tables from fs.c and mbox.c; 
	allow tcs to do the translations

2.  	the rfc-2047 decoding was improved. adjacent 2047-encoded
	"atoms" are pasted together as per the rfc.

i also tightened up the processing of 2047 strings.  the code had been scanning
the insides of 2047 strings for the start of a new 2047-string.

- erik