link libtonezone directly to libm

* Now we properly '-lm' to libtonezone itself.
  Tools that link with libtonezone get it automatically without having
  to individually link it.
  - dahdi_cfg historically needed -lm, but no longer does.

* Also use "autoscan" to refresh "configure.ac":
  - Added missing tests
  - Move AC_CHECK_HEADERS() to their correct location (before testing
    libraries).
* Fixes the following (on Ubuntu-14.04):
      CCLD     dahdi_cfg
    ./.libs/libtonezone.so: undefined reference to `sin'
    ./.libs/libtonezone.so: undefined reference to `cos'
    ./.libs/libtonezone.so: undefined reference to `pow'
    collect2: error: ld returned 1 exit status
    make[2]: *** [dahdi_cfg] Error 1

Signed-off-by: Tzafrir Cohen <tzafrir.cohen@xorcom.com>

Makefile.am

@@ -74,14 +74,15 @@ libtonezone_la_SOURCES	= \
 dahdiinclude_HEADERS	= tonezone.h
 libtonezone_la_CFLAGS	= $(CFLAGS) -I$(srcdir) -DBUILDING_TONEZONE
 libtonezone_la_LDFLAGS	= -version-info "$(LTZ_CURRENT):$(LTZ_REVISION):$(LTZ_AGE)"
+libtonezone_la_LIBADD	= -lm
 
 if PBX_PCAP
 noinst_PROGRAMS		+= dahdi_pcap
 dahdi_pcap_LDADD	= -lpcap
 endif
 
-patlooptest_LDADD	= libtonezone.la -lm
-fxstest_LDADD		= libtonezone.la -lm
+patlooptest_LDADD	= libtonezone.la
+fxstest_LDADD		= libtonezone.la
 fxotune_LDADD		= -lm
 dahdi_speed_CFLAGS	= -O2
 
@@ -93,7 +94,7 @@ dahdi_tool_CFLAGS	= $(CFLAGS) $(NEWT_INCLUDE)
 dahdi_tool_LDADD	= $(NEWT_LIB)
 endif
 
-dahdi_cfg_LDFLAGS	= -lm -lpthread
+dahdi_cfg_LDFLAGS	= -lpthread
 dahdi_cfg_LDADD		= libtonezone.la
 
 udevrulesdir	= @udevrulesdir@

configure.ac

@@ -68,8 +68,6 @@ AC_CONFIG_HEADER(autoconfig.h)
 # This needs to be before any macros that use the C compiler
 AC_GNU_SOURCE
 
-AC_CHECK_HEADERS([sys/soundcard.h linux/soundcard.h])
-
 AC_CHECK_TOOL([LD], [ld])
 
 # Checks for programs.
@@ -160,6 +158,22 @@ else
 fi
 AC_SUBST(DAHDI_DECLARATION_AFTER_STATEMENT)
 
+# Checks for header files.
+AC_CHECK_HEADERS([sys/soundcard.h linux/soundcard.h])
+AC_CHECK_HEADERS([arpa/inet.h fcntl.h limits.h netinet/in.h stdint.h stdlib.h string.h sys/ioctl.h sys/param.h sys/socket.h sys/time.h syslog.h unistd.h])
+
+# Checks for typedefs, structures, and compiler characteristics.
+AC_C_INLINE
+AC_TYPE_SIZE_T
+AC_TYPE_SSIZE_T
+AC_TYPE_UINT16_T
+AC_TYPE_UINT32_T
+AC_TYPE_UINT8_T
+
+# Checks for libraries.
+AC_CHECK_LIB([m], [cos])
+AC_CHECK_LIB([pthread], [pthread_create])
+
 AST_EXT_LIB_SETUP([DAHDI], [DAHDI], [dahdi])
 AST_EXT_LIB_SETUP([NEWT], [newt], [newt])
 AST_EXT_LIB_SETUP([USB], [usb], [usb])
@@ -181,6 +195,9 @@ AM_CONDITIONAL([PBX_NEWT], [test "$PBX_NEWT" = "1"])
 AM_CONDITIONAL([PBX_PCAP], [test "$PBX_PCAP" = "1" -a "$DAHDI_TXMIRROR" = "1"])
 
 AC_CHECK_FUNCS([semtimedop])
+AC_CHECK_FUNCS([alarm bzero gettimeofday memset pow regcomp select socket strcasecmp strchr strdup strerror strrchr strstr strtol strtoul])
+AC_FUNC_ERROR_AT_LINE
+AC_FUNC_MALLOC
 
 # What the user asked for? libusb/libusbx
 AC_ARG_WITH([libusbx],