Several corrections & changes to what has been stated in revision 1.45

1) The maketgz script does not insert the timestamp in curlver.h,
   it actually updates it. For CVS versions it is the "CVS" string.

2) testcurl.pl will always print the "date" string which represents
   the moment the test build is run.

3) testcurl.pl may not print the "timestamp" string since the script
   may end before it is printed out. (i.e. unable to update from CVS)

4) The "timestamp" string printed will be the same as the "date" one
   unless one of the following conditions is met.

   *) It is a tarball-based build. Timestamp will be creation time.

   *) CVS update has been done. Timestamp will be end of CVS update.