Squashed 'src/dmclock/' changes from 64bcc6e..3408cb8

Squashed 'src/dmclock/' changes from 64bcc6e..3408cb8

3408cb8 Merge pull request #33 from ceph/wip-move-make-options-up
f2099ec Moved the check for cmake's DO_NOT_DELAY_TAG_CALC to the top level, so it will affect how tests are built.
437b247 Merge pull request #32 from ceph/wip_add_void_comments
18dd014 Add documentation as to why there are empty void references.
3ddfa39 Merge pull request #28 from Yan-waller/wip-waller-0710dmclockgettime
57520df Merge pull request #31 from dingdangzhang/master
4cad292 delete redundant break statement
b179f3b Merge pull request #29 from tchaikov/wip-cmake
76d5f35 cmake: build gtest if not found
9896fef Merge pull request #30 from tchaikov/wip-move
d72fac1 do FRIEND_TEST manually
f4b155d enforce move semantics of request types
8a2ad2a replace gettimeofday() with clock_gettime() function
b84ccf9 Merge pull request #27 from ceph/joelin-master-ei
34a6e25 Set compiler flags at higher level CMakeLists.txt file, so they apply to sim and test, and so earlier versions of GCC know to use c++11 standard. Clean up cmake files in general.
bad581a Move the PrCtl data structure into a separate header file that can be included where needed in the future. Also, to avoid potential naming conflicts with ceph's PrCtl.h, prefix the filename with "dmc".
1b227bf Merge pull request #25 from badone/wip-test_dmclock_server-coredump
ee1866e dmclock: Don't dump core when using EXPECT_DEATH_IF_SUPPORTED

git-subtree-dir: src/dmclock
git-subtree-split: 3408cb8f3c20d1956d8a08f15958627fbb60e733