Merge changes from PR #47 related to windows platform support.
Add full windows platform support including correct error checking and working regression tests and examples.
Remove need to build applications using libcoap with -DWITH_POSIX and to include coap_config.h. This applies to the examples as well.
Resume the cleaning of the public header files, no functional changes.
Reformatting the infos in the head of the header files, restructure header
inclusion check to be more generic. Reorder some include directives in a
alphabetical order. Remove including instructions for C++ stuff, it's
already done in the coap.h header, and the user only has to include this
header file.
Dropping the prefixing of the include guarding of uthash.h because it would
cause trouble with the macro handling in TinyDLS.
Thanks Olaf for reminding this!
In preparation for changing the make buildsystem to a fully autotools
controlled system moving the core libcoap source files to a better logical
place.
All the library related header files moving to include/coap/ to get
all the public and local header files in a separate place. Also moving
the C source files of the libcoap library to the folder src/.