Ticket #2501: 'lib' should be independ to 'src' directory

Added base support for unit tests (see http://check.sourceforge.net/ for details).

Signed-off-by: Slava Zanko <slavazanko@gmail.com>

acinclude.m4

@@ -9,3 +9,4 @@ m4_include([m4.include/mc-with-screen.m4])
 m4_include([m4.include/ac-g-module-supported.m4])
 m4_include([m4.include/mc-vfs.m4])
 m4_include([m4.include/mc-version.m4])
+m4_include([m4.include/mc-tests.m4])

configure.ac

@@ -489,6 +489,8 @@ if test "x$enable_werror" = xyes; then
 fi
 CFLAGS="$mc_configured_cflags $CFLAGS_OPTS $CFLAGS"
 
+MC_UNIT_TESTS
+
 AC_SUBST(CFLAGS)
 AC_SUBST(CPPFLAGS)
 AC_SUBST(LDFLAGS)

m4.include/mc-tests.m4

@@ -0,0 +1,25 @@
+dnl @synopsis MC_UNIT_TESTS
+dnl
+dnl Check if unit tests enabled
+dnl
+dnl @author Slava Zanko <slavazanko@gmail.com>
+dnl @version 2011-02-10
+dnl @license GPL
+dnl @copyright Free Software Foundation, Inc.
+
+AC_DEFUN([MC_UNIT_TESTS],[
+
+    AC_ARG_ENABLE(
+        [tests],
+        AC_HELP_STRING([--enable-tests], [Enable unit tests (see http://check.sourceforge.net/)] )
+    )
+
+    if test x$enable_tests != xno; then
+        PKG_CHECK_MODULES(
+            CHECK,
+            [check >= 0.9.0],
+            [have_check=yes],
+            [AC_MSG_WARN(['Check' utility not found. Check your environment])])
+    fi
+    AM_CONDITIONAL(HAVE_TESTS, test x"$have_check" = "xyes")
+])