Merge branch 't/build_system_overhaul'

This topic was quite some PITA to maintain since its commits heavily
conflict with the changes of all other topic branches which touch
the build system. Cooking since 2013-12-01 and tested on FreeBSD,
NetBSD and on different Linux systems.

	abb080 Rebuild error2.h on Makefile changes.
	71b616 manual: Move crypt library to the list of optional packages.
	185c67 build: Don't insist on curses for CLI support.
	474d4d build: Rewrite objlist_to_errlist().
	1453e8 build: Reorder Makefile.real.
	7fb39c build: Split Makefile.in.
	d0ddd2 build: Reorder variables in Makefile.in.
	61cc38 build: Add Make variable for clock_gettime_ldflags.
	976651 build: Add Make variable for PACKAGE_TARNAME.
	19b0d3 build: Introduce Make variables for objects.
	fe7666 build: Combine link rules.
	2440c4 build: Introduce $prefixed_executables.
	2f113b build: Combine rules for object files.
	761d9b build: Define Make variables for cppflags.
	386572 build: Remove two unused variables from Makefile.in.
	40439a build: Collect audio format handlers in afh section.
	e926e8 build: Move relevant parts to filter section.
	b399d6 build: Move relevant parts to gui section.
	1781cc build: Move relevant parts to fade section.
	0f4790 build: Move relevant parts to audiod section.
	4e9788 build: Move relevant parts to client section.
	0c8626 build: Move relevant parts to server section.
	755904 build: Create section for para_audioc.
	d952d6 build: Create section for para_write.
	9734df build: Create section for para_play.
	14dee3 build: Create section for para_afh.
	b1abc2 build: Create section for para_recv.
	bfd5b5 build: Create section for para_filter.
	9139d9 build: ldflags conversion: coreaudio.
	30f966 build: ldflags conversion: libcurses.
	15880b build: ldflags conversion: libnsl.
	516421 build: ldflags conversion: libsocket.
	ce8273 build: ldflags conversion: libgcrypt.
	ad3573 build: ldflags conversion: libssl.
	52ac85 build: ldflags conversion: libosl.
	37083e build: ldflags conversion: libsamplerate.
	7de07a build: ldflags conversion: libreadline.
	0e9f1c build: ldflags conversion: libao.
	ecac89 build: ldflags conversion: alsa.
	6c632d build: ldflags conversion: liboss.
	e74262 build: ldflags conversion: libflac.
	648197 build: ldflags conversion: libmad.
	91ed86 build: ldflags conversion: libfaad.
	8ee713 build: ldflags/cppflags conversion: libopus.
	b6c705 build: cppflags/ldflags conversion: libspeex.
	7aa414 build: ldflags conversion: libvorbis.
	80a639 build: ldflags conversion: libogg.
	c79cdc build: cppflags/ldflags conversion: libid3tag
	a02396 build: Remove duplicates from $all_objs.
	d2fc4d build: Remove inactive DEBUG_CPPFLAGS.
	e8f310 build: Replace error2.pl by error2.c.
	06e33e build: Fix filter output of configure summary.
	994889 build: Convert remaining object lists to one object per line format.
	782e47 build: Separate curses detection from gui configuration.
	fbe4b0 build: Move down fade section.
	003815 build: Add object "cmdline" suffix only once.
	3097e5 INSTALL: Add an example for cross-compiling.
	e8b555 build: Fix make install for cross builds.
	aab667 build: Generate man pages directly from ggo files.
	9a8a15 build: Remove fnmatch, malloc, realloc tests.
	2dcdd9 build: Make crypto optional.
	f23353 build: Make audiod optional.
	98b801 build: Build para_client only if crypto lib was found.
	17ed11 build: Create a separate section for para_server.
	02c1e0 build: Compute $all_errlist_objs.
	4ec04c build: Replace $extras by per-executable variable.
	39707e build: Remove two dead recipes from Makefile.in.
	9fc99c build: Remove check for buggy snprintf().

diff --cc NEWS
index 6c92bd7b7fabf3f601bb220dbc319df1ae1ea0c2,980f613a7915e1a48d429ba17993d57572f4184f..29a74a4ca910634c55113e3288b937a1e0831dfe
--- 1/NEWS
--- 2/NEWS
+++ b/NEWS
@@@ -5,13 -5,9 +5,24 @@@ NEW
  0.5.1 (to be announced) "temporary implication"
  ----------------------------------------------
  
- Lots of fixes and improvements all over the place.
 -      - audiod improvements and fixes.
 -      - buffer tree robustness improvements.
 -      - cleanup of the mood subsystem.
++Lots of fixes and improvements all over the place, and a major overhaul
++of the build system.
 +
 +      - Audiod improvements and fixes.
 +      - Buffer tree robustness improvements.
 +      - Cleanup of the mood subsystem.
 +      - Fixes and cleanups for the flac decoder.
 +      - Latency improvements for the ogg/opus decoder.
++      - Crypto support is now optional. On systems without
++        openssl/gcrypt, the build succeeds but para_server,
++        para_audiod, para_client won't be built.
++      - The build system now works for cross-compile setups.
++      - The dependency tree has been flattened, which speeds up
++        builds and avoids to recreate the man pages on every change.
++      - The error code helper has been rewritten from perl to C,
++        which further improves build time.
++      - Many small bugs in the build system have been identified
++        and fixed.
  
  ----------------------------------------
  0.5.0 (2013-08-23) "invertible validity"