* Rename prepare_sources.py to configure.py; the operation is similar to
autoconf ./configure so the association is useful.
* Rename make_dist.py to dist.py.
* Generate only one source set (combined or separate) for one run of
configure.py.
* Change dist.py to run configure.py three times to generate the default
source sets.
* Use an autodeleted temporary directory for preparing sources, which
removes some of the manual temporary file handling.
On FreeBSD arpa/inet.h doesn't provide sockaddr_in, which is provided by
netinet/in.h. Since netinet/in.h is POSIX and arpa/inet.h is SUSv2, and
Duktape only needs defines from netinet/in.h, switch to using that header.
Scanbuild fixes:
* duk_cmdline.c realloc() failure could leak memory, fixed.
* Other fixed scanbuild errors were harmless.
* Remaining errors are invalid memory access in panic (intentional
segfault) and a Date handling case where garbage data is intentionally
assigned as doing so is harmless and intended.
Avoid unnecessary index re-check in num coercion.
* Add AppRequest example with "CommandLine" custom command which provides
the C argv[].
* Add AppNotify example with "DebuggerHandleFile" custom notify when running
code from files.
* Set SIGPIPE handler to SIG_IGN when signal setup is enabled. This avoids
hard exits due to SIGPIPE when debugger transport connections break.
* Add --reattach option to allow the auto-reattach test to be done without
modifying duk_cmdline.c.
Add global bindings readFile() and writeFile() for easier testing
of JSON parsing etc. These are in no way official Duktape bindings,
just part of the 'duk' command (when enabled).