Auto merge of #929 - bitcartel:zc.v0.11.2.z2_fix_717, r=ebfull

Fix issue #717 t

Fix issue #717 where if addrman is starved of addresses (e.g. on testnet)
the Select_() function will loop endlessly trying to find an address,
and therefore eat up 100% cpu time on the 'opencon' thread.

Solution is to (1) add a delay to the loop and (2) restrict the number
of attempts to find an address.  On exiting the loop, we return
to an outer loop in net.cpp which will sleep, add seed nodes and
calculate new addresses.

src/Makefile.test.include

@@ -39,6 +39,7 @@ GENERATED_TEST_FILES = $(JSON_TEST_FILES:.json=.json.h) $(RAW_TEST_FILES:.raw=.r
 BITCOIN_TESTS =\
   test/arith_uint256_tests.cpp \
   test/bignum.h \
+  test/addrman_tests.cpp \
   test/alert_tests.cpp \
   test/allocator_tests.cpp \
   test/base32_tests.cpp \