build: Use more gnulib modules.

* autogen.sh (GNULIB_MODULES): Add read-file.
Copy also config.guess and config.sub.
* lib/Makefile.am (BUILT_SOURCES, MOSTLYCLEANDIRS): New variables.
(libgp_a_SOURCES): Remove getline.h, getline.cc.
* lib/getline.h: Remove file.
* lib/getline.cc: Remove file.
* src/configure.ac: Change config.h to also include ../lib/config.h.
* src/output.cc: Include <config.h> first.
* src/search.cc: Likewise.
* src/bool-array.cc: Include <config.h>.
* src/keyword.cc: Likewise.
* src/keyword-list.cc: Likewise.
* src/hash-table.cc: Likewise.
* src/main.cc: Likewise.
* src/options.cc: Likewise.
* src/positions.cc: Likewise.
* src/version.cc: Likewise.
* src/input.cc: Likewise. Include read-file.h instead of getline.h.
(Input<KT>::read_input): Use fread_file instead of get_delim.

lib/.gitignore

@@ -1,8 +1,69 @@
 # Files brought in by gnulib-tool:
 /gnulib-m4/
 /Makefile.gnulib
-/dummy.c
+/_Noreturn.h
+/alloca.in.h
+/arg-nonnull.h
+/assert.in.h
+/c++defs.h
+/cloexec.c
+/cloexec.h
+/close.c
+/dup2.c
+/errno.in.h
+/fcntl.c
+/fcntl.in.h
+/fd-hook.c
+/fd-hook.h
 /filename.h
+/fopen.c
+/free.c
+/fstat.c
+/ftell.c
+/ftello.c
+/getdtablesize.c
+/idx.h
+/intprops-internal.h
+/inttypes.in.h
+/limits.in.h
+/lseek.c
+/malloc.c
+/malloca.c
+/malloca.h
+/memset_explicit.c
+/msvc-inval.c
+/msvc-inval.h
+/msvc-nothrow.c
+/msvc-nothrow.h
+/open.c
+/pathmax.h
+/read-file.c
+/read-file.h
+/realloc.c
+/stat-time.c
+/stat-time.h
+/stat-w32.c
+/stat-w32.h
+/stat.c
+/stdckdint.in.h
+/stddef.in.h
+/stdint.in.h
+/stdio-impl.h
+/stdio-read.c
+/stdio-write.c
+/stdio.in.h
+/stdlib.c
+/stdlib.in.h
+/string.in.h
+/sys_stat.in.h
+/sys_types.in.h
+/time.in.h
+/unistd.c
+/unistd.in.h
+/verify.h
+/warn-on-use.h
+/wchar.in.h
+/xalloc-oversized.h
 
 # Files generated by the autotools:
 /aclocal.m4