* refine PADDLE_THROW, test=develop

* refine error msg, test=develop

* refine cuda error, test=develop

* follow comments, test=develop

* fix compile problem, test=develop

* fix bug, test=develop

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.

test=develop

* add recorded cuda memory apis, fix typo, test=develop

* add more ut, test=develop

* follow comments, test=develop

* fix py35 incompatible issues, test=develop

* 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

* refine err msg of out of gpu memory, test=develop

* refine err msg again, test=develop

* refine errog message again, test=develop

* follow reviewer's comments, test=develop

* add retry_allocator for gpu, test=develop

* follow chengduoZH's comments, test=develop

* follow huihuang's comments,test=develop

* change f,l in enforce.h to be file,line, test=develop

* increase code coverage by adding unittests, test=develop

* fix CMakeLists.txt, test=develop

test=develop

* replace part of PADDLE_ASSERT to PADDLE_ENFORCE

test=develop

* remove unused fallback_alloc_size_

* add unit-test of CUDAPinnedAllocator

test=develop

* fix gpu_info, test=develop

* fix reserving gpu memory calculation bug, add fraction=1 unittest, test=develop

* fix bug again for reserving size, test=develop

GPU allocation uses fraction of available memory, also fix the GetUsed without lock

* remove unnecessary set_devices

modify allocator strategy
remove changes of legacy buddy_allocator
test=develop

test=develop

test=develop

test=develop

test=develop

Fix code to support cpplint syntax check

test=develop

* memory module

* "fix ci"