Rearrange initial config checks: AC, AM, compiler, libtool.

Removed some repeated and unused prog checks.

configure.ac

@@ -14,42 +14,14 @@ AC_CONFIG_MACRO_DIR([build-aux/m4])
 
 AC_CANONICAL_HOST
 
-dnl By default, libtool for mingw refuses to link static libs into a dll for
-dnl fear of mixing pic/non-pic objects, and import/export complications. Since
-dnl we have those under control, re-enable that functionality.
-
-case $host in
-  *mingw*)
-     lt_cv_deplibs_check_method="pass_all"
-  ;;
-esac
-
-LT_INIT([disable-shared])
-
 AH_TOP([#ifndef BITCOIN_CONFIG_H])
 AH_TOP([#define BITCOIN_CONFIG_H])
 AH_BOTTOM([#endif //BITCOIN_CONFIG_H])
 
-# This m4 will only be used if a system copy cannot be found. This is helpful
-# on systems where autotools are installed but the pkg-config macros are not in
-# a default location. It is currently used for building on OSX where autotools
-# are preinstalled but pkg-config comes from macports or homebrew. It should
-# probably be removed when building on <= 10.6 is no longer supported.
-m4_include([pkg.m4])
-
 dnl faketime breaks configure and is only needed for make. Disable it here.
 unset FAKETIME
 
-if test "x${CXXFLAGS+set}" = "xset"; then
-  CXXFLAGS_overridden=yes
-else
-  CXXFLAGS_overridden=no
-fi
-
-dnl ==============================================================
-dnl Setup for automake
-dnl ==============================================================
-
+dnl Automake init set-up and checks
 AM_INIT_AUTOMAKE([no-define subdir-objects foreign])
 
 dnl faketime messes with timestamps and causes configure to be re-run.
@@ -59,17 +31,27 @@ AM_MAINTAINER_MODE([enable])
 dnl make the compilation flags quiet unless V=1 is used
 m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
 
-dnl Checks for programs.
+dnl Compiler checks (here before libtool).
+if test "x${CXXFLAGS+set}" = "xset"; then
+  CXXFLAGS_overridden=yes
+else
+  CXXFLAGS_overridden=no
+fi
 AC_PROG_CXX
-AC_PROG_CC
-AC_PROG_CPP
-AC_PROG_CXXCPP
-AC_PROG_INSTALL
-AC_PROG_OBJC
-AC_PROG_LN_S
 m4_ifdef([AC_PROG_OBJCXX],[AC_PROG_OBJCXX])
-AC_PROG_MKDIR_P
-AC_PROG_SED
+
+dnl By default, libtool for mingw refuses to link static libs into a dll for
+dnl fear of mixing pic/non-pic objects, and import/export complications. Since
+dnl we have those under control, re-enable that functionality.
+case $host in
+  *mingw*)
+     lt_cv_deplibs_check_method="pass_all"
+  ;;
+esac
+dnl Libtool init checks.
+LT_INIT([disable-shared])
+
+dnl Check/return PATH for base programs.
 AC_PATH_TOOL(AR, ar)
 AC_PATH_TOOL(RANLIB, ranlib)
 AC_PATH_TOOL(STRIP, strip)
@@ -81,6 +63,15 @@ AC_PATH_PROG([GIT], [git])
 AC_PATH_PROG(CCACHE,ccache)
 AC_PATH_PROG(XGETTEXT,xgettext)
 AC_PATH_PROG(HEXDUMP,hexdump)
+
+# This m4 will only be used if a system copy cannot be found. This is helpful
+# on systems where autotools are installed but the pkg-config macros are not in
+# a default location. It is currently used for building on OSX where autotools
+# are preinstalled but pkg-config comes from macports or homebrew. It should
+# probably be removed when building on <= 10.6 is no longer supported.
+m4_include([pkg.m4])
+
+dnl pkg-config check.
 PKG_PROG_PKG_CONFIG
 
 # Enable wallet