Refinement of project structure.

- components renaming and moving:
   - liballocator -> mem;
   - libcoreint -> vm;
   - libecmaobjects -> ecma/base;
   - libecmaoperations -> ecma/operations;
   - libecmabuiltins -> ecma/builtins;
   - libjsparser -> parser/js;
   - libintstructs -> parser/collections;
   - liboptimizer -> parser/js;
   - libperipherals -> ../plugins/lib_device_stm;
   - libruntime -> jrt;
 - generated.h now is created as intermediate during build;
 - benchmarks -> tests/benchmarks;
 - docs -> documentation;
 - demo-applications removed (loop_demo.js -> tests/blinky.js).

Makefile

@@ -116,7 +116,7 @@ precommit: clean
 	@ $(MAKE) unittests_run TESTS_OPTS="--silent"
 	@ echo -e "Unit tests completed successfully. Starting parse-only testing.\n"
 	@ # Parse-only testing
-	@ for path in "./tests/jerry" "./benchmarks/jerry"; \
+	@ for path in "./tests/jerry" "./tests/benchmarks/jerry"; \
           do \
             run_ids=""; \
             for check_target in $(PRECOMMIT_CHECK_TARGETS_NO_VALGRIND_LIST) $(PRECOMMIT_CHECK_TARGETS_VALGRIND_LIST); \