[svn] Upped version number from 1.5.3. to 1.5.3+dev. Because the development source

[svn] Upped version number from 1.5.3. to 1.5.3+dev.  Because the development source
is available via anonymous CVS and desirable features are being added, it's
quite possible for end-users to be getting their hands on development versions.
They may report bugs, so if we don't change the version number, we'll have to
continually followup the statement "I'm using version 1.5.3" with the question
"The FTP archive or the CVS source?"  Better to just make this development
version have a unique number.  Once we're ready to actually release the next
version, we can up the version from 1.5.3+dev to 1.5.4, or 1.6, or whatever it
turns out to be (depending on how much development gets done).

Also made minor updates (dates, email addresses) to wget.texi.