work with libidn < 0.5.6

Added tld_check_name().

Fixed tld_check_name(). idna_to_unicode_lzlz() should never fail,
but return FALSE if 'uc_name == NULL' just in case.

USE_LIBIDN: Added Top-level-domain (TLD) check for host->name.
Only print a warning if check fails.

CURLOPT_FOLLOWLOCATION, libcurl reported error if a redirect happened even if
the new URL would provide the resumed file. Test case 188 added to verify the
fix (together with existing test 99).

djgpp has basename()

about code that won't be reached

Mainly meant to deal with the IRIX case which seems to requrie a "-lgen" lib
to find the basename function and thus without the gen lib, it finds the
header but not the function and our replacement function has a prototype
that doesn't match the IRIX one.

A different approach would be to make configure detect and use -lgen for the
systems that require it.

allow verbose output during this period. Bertrand Demiddelaer reported and
helped fixing.

the multi-threaded resolver does wrong

data as 'char *' and that makes us pass in negative values if there is 8bit
data in the string. Changing to unsigned causes too much warnings or too many
required typecasts to the normal string functions.

included in very recent versions

individual transfers

based) IDN conversion fails. This is really due to a missing suitable
function in the libidn API that I hope we can remove once libidn gets a
function like this.

https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=134133) and not to anyone
involved in the curl project! This happens when you try to curl a file from a
proftpd site using SSL. It seems proftpd sends a somewhat unorthodox PASS
response code (232 instead of 230). I relaxed the response code check to deal
with this and similar cases.

  formposts no longer include the path part. If you _really_ want them, you
  must provide your preferred full file name with CURLFORM_FILENAME.

  Added detection for libgen.h and basename() to configure. My custom
  basename() replacement function for systems without it, might be a bit too
  naive...

  Updated 6 test cases to make them work with the stripped paths.

  app to retrieve the errno variable after a (connect) failure. It will make
  sense to provide this for more failures in a more generic way, but let's
  start like this.