The background is that buddy_allocator_test depends on some big GPU allocations and current machine may not have it. It can cause random failure on cloud machine. After discussion with Shuo Tian, we decided to make buddy_allocator_test exclusive.

* improve save and load behaviour, test=develop

* code cleaning, test=develop

* disable check_guards and update_guards in release version, test=develop

* fix compilation issue, test=develop

* add buddy_allocator speed test data, test=develop

* fix compilation issue, test=develop

* fix comment, test=develop

* update function names according to the google C++ style guide, test=develop

* tweak the test data format, test=develop

* move buddy_allocator_test_data to paddle/fluid/testdata, test=develop

* add accessor and mutator for Desc, test=develop