curl_global_cleanup().  Update corresponding man pages...

Improve the logic in curl_global_cleanup() and curl_global_init() so that
they are not called twice if the application libraries have been
initialized and make sure to reset the init flags in curl_global_cleanup().

resumed downloads

strequal.o as well!

This is my first CVS commit :), what it does:

- Makes sure that parts of the cURL library don't get initialized twice
- Makes sure that we only free what we initialize

be defined as many include files as possible (Solaris req)

specify exactly what global parts to init. Thanks to Sterling Hughes really
for arguing wisely.

   If your system, such as Solaris 2.7, lacks the strtok_r() prototype in
   string.h, then you'll face a bunch of warnings on all instances
   where strtok_r() is used.

   There's not much we can do about it. Adding a prototype here screws
   everything up on other platforms! :-(

curl_global_* functions

afterwards (bug #426442)

into the DOS kind!