use CFLAGS from ncurses*-config, if present (#745)

Fixes #695.

configure.ac

@@ -164,19 +164,25 @@ m4_define([HTOP_CHECK_SCRIPT],
 [
    if test ! -z "m4_toupper($HTOP_[$1]_CONFIG_SCRIPT)"; then
       # to be used to set the path to ncurses*-config when cross-compiling
-      htop_config_script=$(m4_toupper($HTOP_[$1]_CONFIG_SCRIPT) --libs 2> /dev/null)
+      htop_config_script_libs=$(m4_toupper($HTOP_[$1]_CONFIG_SCRIPT) --libs 2> /dev/null)
+      htop_config_script_cflags=$(m4_toupper($HTOP_[$1]_CONFIG_SCRIPT) --cflags 2> /dev/null)
    else
-      htop_config_script=$([$4] --libs 2> /dev/null)
+      htop_config_script_libs=$([$4] --libs 2> /dev/null)
+      htop_config_script_cflags=$([$4] --cflags 2> /dev/null)
    fi
    htop_script_success=no
    htop_save_LDFLAGS="$LDFLAGS"
-   if test ! "x$htop_config_script" = x; then
-      LDFLAGS="$htop_config_script $LDFLAGS"
+   htop_save_CFLAGS="$CFLAGS"
+   if test ! "x$htop_config_script_libs" = x; then
+      LDFLAGS="$htop_config_script_libs $LDFLAGS"
+      CFLAGS="$htop_config_script_cflags $CFLAGS"
       AC_CHECK_LIB([$1], [$2], [
          AC_DEFINE([$3], 1, [The library is present.])
-         LIBS="$htop_config_script $LIBS "
+         LIBS="$htop_config_script_libs $LIBS "
          htop_script_success=yes
-      ], [])
+      ], [
+        CFLAGS="$htop_save_CFLAGS"
+      ])
       LDFLAGS="$htop_save_LDFLAGS"
    fi
    if test "x$htop_script_success" = xno; then