SERVER-8864 Fixed recv exception handling in httpClientTest and web server
SERVER-10513 log warning about deprecation of votes in replica set config
SERVER-10460 ensure IndexRebuilder runs at startup on secondaries
SERVER-10460 fix slowNightly/index_retry.js failure
SERVER-6376 no longer trigger elections or reconnections for replica set reconfigs consisting only of tag changes
SERVER-9516 Logic of system.users schema upgrade process.

Includes AuthorizationManagerExternalState interface changes and implementation
in the mock, plus unit tests.
SERVER-9516 Initialize local variable to satisfy a compiler.

Newer compilers correctly identify that durableVersion in this patch is always
initialized before use, but some older compilers cannot perform a sufficient
analysis, and issue a spurious warning.