minor: update readme for 26compat branch
CXX-133 Update travis configuration to run client examples
minor: authTest example now works on MonogDB < 2.5.3
CXX-126 Backport rc1..rc2 changes

CXX-126 Backport relevant server repo changes applied between rc1 and rc2
Merge branch '26compat' into legacy
CXX-145 remove SyncClusterConnection
CXX-146 Remove ticketholder.h
CXX-147 Remove shared_mutex_win.hpp
CXX-153 Drop needless dependency on boost program options
CXX-156 Remove LastError, SpinLock, and DiagStr from driver
CXX-39 add coverage target(lcov)
CXX-39 add coverage artifacts to .gitignore
minor: disable TTL example