With the curl memory tracking feature decoupled from the debug build feature,
CURLDEBUG and DEBUGBUILD preprocessor symbol definitions are used as follows:
CURLDEBUG used for curl debug memory tracking specific code (--enable-curldebug)
DEBUGBUILD used for debug enabled specific code (--enable-debug)
finds out its return type and the types of its arguments. Added definitions
for non-configure systems config files, and introduced macro sreadfrom which
will be used on udp sockets as a recvfrom() wrapper.
versions of ws2tcpip.h do not have the definition. It seems that when
the socklen_t definition is missing from ws2tcpip.h the definition for
INET_ADDRSTRLEN is also missing, and that when one definition is present
the other one also is available.
Check for lowercase 'bool' type at configuration stage. If not available
provide a suitable replacement with a type definition of 'unsigned char'
in setup_once.h
Move definitions of TRUE and FALSE to setup_once.h
making them available to any source code file which includes "setup.h".
Macro SOCKERRNO / SET_SOCKERRNO() returns / sets the *socket-related* errno
(or equivalent) on this platform to hide platform details to code using it.
Macro ERRNO / SET_ERRNO() returns / sets the NOT *socket-related* errno
(or equivalent) on this platform to hide platform details to code using it.
defining HAVE_SIGNAL_H if the header is available.
Added a check in configure that tests if the sig_atomic_t type is
available, defining HAVE_SIG_ATOMIC_T if it is available. Providing
a suitable default in setup_once.h if not available.
Added a check in configure that tests if the sig_atomic_t type is
already defined as volatile, defining HAVE_SIG_ATOMIC_T_VOLATILE
if it is available and already defined as volatile.
