autotools: install themes during 'make install'

Default path for themes is ${pkgdatadir}/themes that usualy equals to
/usr/share/profanity/themes. This patch also introduces new option
--with-themes[=PATH] that specifies installation path. This option can
be used for cancel of installation at all: --without-themes.

References: issue #323

configure.ac

@@ -42,6 +42,8 @@ AC_ARG_WITH([libxml2],
     [AS_HELP_STRING([--with-libxml2], [link with libxml2 instead of expat])])
 AC_ARG_WITH([xscreensaver],
     [AS_HELP_STRING([--with-xscreensaver], [use libXScrnSaver to determine idle time])])
+AC_ARG_WITH([themes],
+    [AS_HELP_STRING([--with-themes[[=PATH]]], [install themes (default yes)])])
 
 ### Select first existing xml library among expat and libxml2
 PARSER=""
@@ -192,6 +194,15 @@ elif test "x$enable_otr" = x; then
         [AC_MSG_NOTICE([libotr not found, otr encryption support not enabled])])
 fi
 
+AS_IF([test "x$with_themes" = xno],
+    [THEMES_INSTALL="false"],
+    [THEMES_INSTALL="true"])
+AS_IF([test "x$with_themes" = xno -o "x$with_themes" = xyes -o "x$with_themes" = x],
+    [THEMES_PATH='${pkgdatadir}/themes'],
+    [THEMES_PATH="$with_themes"])
+AC_SUBST(THEMES_PATH)
+AM_CONDITIONAL([THEMES_INSTALL], "$THEMES_INSTALL")
+
 ### cmocka is required only for tests, profanity shouldn't be linked with it
 ### TODO: pass cmocka_CFLAGS and cmocka_LIBS to Makefile.am
 PKG_CHECK_MODULES([cmocka], [cmocka], [],
@@ -206,6 +217,7 @@ AM_CFLAGS="-Wall -Wno-deprecated-declarations"
 AS_IF([test "x$PACKAGE_STATUS" = xdevelopment],
     [AM_CFLAGS="$AM_CFLAGS -Wunused -Werror"])
 AM_CPPFLAGS="$AM_CPPFLAGS $glib_CFLAGS $curl_CFLAGS $libnotify_CFLAGS"
+AM_CPPFLAGS="$AM_CPPFLAGS -DTHEMES_PATH=\"$THEMES_PATH\""
 LIBS="$LIBS $glib_LIBS $curl_LIBS $libnotify_LIBS"
 
 AC_SUBST(AM_CFLAGS)
@@ -225,5 +237,7 @@ echo "AM_CFLAGS      : $AM_CFLAGS"
 echo "AM_CPPFLAGS    : $AM_CPPFLAGS"
 echo "LIBS           : $LIBS"
 echo "XML Parser     : $PARSER"
+echo "Install themes : $THEMES_INSTALL"
+echo "Themes path    : $THEMES_PATH"
 echo ""
 echo "Now you can run \`make' to build profanity"