files.[h|cpp] is bound to be abused with junk, replace with
android_get_control_file.[h|cpp]. Plus some sundry cleanup.
Test: gTest libcutils-tests, logd-unit-tests, liblog-unit-tests,
logcat-unit-tests and init_tests
Bug: 32450474
Change-Id: Ibd4a7aa4624ea19a43d1f98a3c71ac37805d36b5
Fixes libcutils multi-buffer write interface to be more friendly and
hooks into it from the fastboot Socket class.
Bug: http://b/26558551
Change-Id: Ibb3a8428fc379755602de52722c1260f9e345bc0