Remove HAVE_W32API_H definition and checks

All still supported versions of MinGW/Cygwin provide w32api.h file, so
there is no need to test for it.

This allows to simplify the code, but also remove the definition of
HAVE_W32API_H from bake- and makefiles and this, in turn, allows to get
rid of extra flags in MinGW format entirely, as we don't support gcc
2.95 for which they were originally needed neither.

configure

@@ -1033,6 +1033,7 @@ infodir
 docdir
 oldincludedir
 includedir
+runstatedir
 localstatedir
 sharedstatedir
 sysconfdir
@@ -1466,6 +1467,7 @@ datadir='${datarootdir}'
 sysconfdir='${prefix}/etc'
 sharedstatedir='${prefix}/com'
 localstatedir='${prefix}/var'
+runstatedir='${localstatedir}/run'
 includedir='${prefix}/include'
 oldincludedir='/usr/include'
 docdir='${datarootdir}/doc/${PACKAGE_TARNAME}'
@@ -1718,6 +1720,15 @@ do
   | -silent | --silent | --silen | --sile | --sil)
     silent=yes ;;
 
+  -runstatedir | --runstatedir | --runstatedi | --runstated \
+  | --runstate | --runstat | --runsta | --runst | --runs \
+  | --run | --ru | --r)
+    ac_prev=runstatedir ;;
+  -runstatedir=* | --runstatedir=* | --runstatedi=* | --runstated=* \
+  | --runstate=* | --runstat=* | --runsta=* | --runst=* | --runs=* \
+  | --run=* | --ru=* | --r=*)
+    runstatedir=$ac_optarg ;;
+
   -sbindir | --sbindir | --sbindi | --sbind | --sbin | --sbi | --sb)
     ac_prev=sbindir ;;
   -sbindir=* | --sbindir=* | --sbindi=* | --sbind=* | --sbin=* \
@@ -1855,7 +1866,7 @@ fi
 for ac_var in	exec_prefix prefix bindir sbindir libexecdir datarootdir \
 		datadir sysconfdir sharedstatedir localstatedir includedir \
 		oldincludedir docdir infodir htmldir dvidir pdfdir psdir \
-		libdir localedir mandir
+		libdir localedir mandir runstatedir
 do
   eval ac_val=\$$ac_var
   # Remove trailing slashes.
@@ -2008,6 +2019,7 @@ Fine tuning of the installation directories:
   --sysconfdir=DIR        read-only single-machine data [PREFIX/etc]
   --sharedstatedir=DIR    modifiable architecture-independent data [PREFIX/com]
   --localstatedir=DIR     modifiable single-machine data [PREFIX/var]
+  --runstatedir=DIR       modifiable per-process data [LOCALSTATEDIR/run]
   --libdir=DIR            object code libraries [EPREFIX/lib]
   --includedir=DIR        C header files [PREFIX/include]
   --oldincludedir=DIR     C header files for non-gcc [/usr/include]
@@ -22886,19 +22898,6 @@ TOOLKIT_INCLUDE=
 WIDGET_SET=
 
 if test "$USE_WIN32" = 1 ; then
-    for ac_header in w32api.h
-do :
-  ac_fn_c_check_header_compile "$LINENO" "w32api.h" "ac_cv_header_w32api_h" "
-"
-if test "x$ac_cv_header_w32api_h" = xyes; then :
-  cat >>confdefs.h <<_ACEOF
-#define HAVE_W32API_H 1
-_ACEOF
-
-fi
-
-done
-
     ac_fn_c_check_header_compile "$LINENO" "windows.h" "ac_cv_header_windows_h" "
 "
 if test "x$ac_cv_header_windows_h" = xyes; then :
@@ -27601,7 +27600,7 @@ $as_echo "found in $ac_find_includes" >&6; }
     fi
   fi
 
-            CPPFLAGS="$ac_path_to_include $CPPFLAGS"
+            CPPFLAGS="$CPPFLAGS $ac_path_to_include"
         else
             { $as_echo "$as_me:${as_lineno-$LINENO}: result: not found" >&5
 $as_echo "not found" >&6; }
@@ -29229,7 +29228,7 @@ $as_echo "$wx_cv_cc_visibility_workaround" >&6; }
 
       *-*-solaris2* )
 
-                        CPPFLAGS="-isystem /usr/openwin/include $CPPFLAGS"
+                        CPPFLAGS="$CPPFLAGS -isystem /usr/openwin/include"
 
                         saveLdflags="$LDFLAGS"
         LDFLAGS="$saveLdflags -Wl,-rpath,/"
@@ -38264,10 +38263,12 @@ WXCONFIG_CFLAGS=`echo $WXCONFIG_CFLAGS`
 WXCONFIG_CXXFLAGS=`echo $WXCONFIG_CFLAGS $WXCONFIG_CXXFLAGS`
 
 
-CPPFLAGS=`echo $WXCONFIG_CPPFLAGS \
+CPPFLAGS=`echo \
  -I\\${wx_top_builddir}/lib/wx/include/${TOOLCHAIN_FULLNAME} \
- -I\\${top_srcdir}/include $TOOLKIT_INCLUDE \
- $CPPFLAGS `
+ -I\\${top_srcdir}/include \
+ $CPPFLAGS \
+ $WXCONFIG_CPPFLAGS \
+ $TOOLKIT_INCLUDE`
 
 C_AND_CXX_FLAGS="$DEBUG_CFLAGS $PROFILE_FLAGS $OPTIMISE_CFLAGS"
 CFLAGS=`echo $WXCONFIG_CFLAGS $CWARNINGS $C_AND_CXX_FLAGS $CFLAGS `