configure: build tablet-shell client conditionally

Do not build the tablet-shell client if --disable-tablet-shell is given.

Change --enable-tablet-shell to --disable-tablet-shell in ./configure
--help output, since it is enabled by default. Add a description.

Use proper quoting in the conditional.

Signed-off-by: Pekka Paalanen <ppaalanen@gmail.com>

clients/Makefile.am

@@ -64,7 +64,11 @@ clients_programs =				\
 	$(full_gl_client_programs)
 
 desktop_shell = weston-desktop-shell
+
+if ENABLE_TABLET_SHELL
 tablet_shell = weston-tablet-shell
+endif
+
 screenshooter = weston-screenshooter
 
 noinst_LIBRARIES = libtoytoolkit.a

configure.ac

@@ -213,10 +213,12 @@ AM_CONDITIONAL(BUILD_FULL_GL_CLIENTS,
 
 AM_CONDITIONAL(ENABLE_DESKTOP_SHELL, true)
 
-AC_ARG_ENABLE(tablet-shell, [  --enable-tablet-shell],,
+AC_ARG_ENABLE(tablet-shell,
+              AS_HELP_STRING([--disable-tablet-shell],
+                             [do not build tablet-shell server plugin and client]),,
 	      enable_tablet_shell=yes)
 AM_CONDITIONAL(ENABLE_TABLET_SHELL,
-	       test x$enable_tablet_shell = xyes)
+	       test "x$enable_tablet_shell" = "xyes")
 
 
 AC_ARG_ENABLE(wcap-tools, [  --disable-wcap-tools],, enable_wcap_tools=yes)