Fix .app file and create filter_lib directory

Emakefile

@@ -1,5 +1,6 @@
 {"src/erlydtl/*", [debug_info, {outdir, "ebin"}]}.
 {"src/erlydtl/i18n/*", [debug_info, {outdir, "ebin"}]}.
+{"src/erlydtl/filter_lib/*", [debug_info, {outdir, "ebin"}]}.
 {"src/tests/*", [debug_info, {outdir, "ebintest"}]}.
 {"src/tests/i18n/*", [debug_info, {outdir, "ebintest"}]}.
 {"src/demo/*", [debug_info, {outdir, "ebintest"}]}.

ebin/erlydtl.app

@@ -14,6 +14,7 @@
              erlydtl_parser,
              erlydtl_runtime,
              erlydtl_scanner,
+             erlydtl_slice,
              erlydtl_unittests,
              erlydtl_i18n,
              i18n_manager,