Custom column updates:

Custom column updates:

 - Change apply / prepare / ... as filter to use the field's value, which
   is now stored in fdata as well as cinfo.  Now we don't have to reprocess
   the entire packet list when using these features.  This also prevents
   the use of these features from overwriting custom column information.
   (custom columns can now be used in apply / prepare ... as filter)
 - Break col_expr and col_expr_val out into a struct that is included not only
   in cinfo, but now also fdata.
 - Have col_custom_set_fstr() quote FT_STRING & FT_STRINGZ when storing the
   col_expr_val value (for filter creation).

svn path=/trunk/; revision=24511