Reversion to former xato?.c code.

[Matthias Andree]

Hi,

I've removed the string processing pollutions from the xato?.c files,
the xato?() functions will ONLY succeed when the full string is
parseable. Killing trailing whitespace or trailing "f" characters or
comments doesn't belong into these functions, they are for conversion
only, and allowing trailing whitespace actually made these functions
accept the null string (which is not what we want, and special-casing
this is inefficient and unnecessary).

The functionality we're looking for is now provided for by configfile.c.

This means the user will have to:

1. remove end-of-line comments (until the end-of-line starts in the
   leftmost column ;-)

2. remove trailing "f" characters after floats. They are misleading
   anyways because a) the floating point nature is clearly visible from
   the dot (or exponent), b) a trailing "f" in C numeric constant means
   "float" as opposed to our expected format "double".

Along with the most recent format.c fix, the current configfile.c and
xato?.c files parse bogofilter.cf.example.

-- 
Matthias Andree