Implements view tags as proposed by @UkoeHB in MRL issue
https://github.com/monero-project/research-lab/issues/73
At tx construction, the sender adds a 1-byte view tag to each
output. The view tag is derived from the sender-receiver
shared secret. When scanning for outputs, the receiver can
check the view tag for a match, in order to reduce scanning
time. When the view tag does not match, the wallet avoids the
more expensive EC operations when deriving the output public
key using the shared secret.
bcf3f6af fuzz_tests: catch unhandled exceptions (moneromooo-monero)
3ebd05d4 miner: restore stream flags after changing them (moneromooo-monero)
a093092e levin_protocol_handler_async: do not propagate exception through dtor (moneromooo-monero)
1eebb82b net_helper: do not propagate exceptions through dtor (moneromooo-monero)
fb6a3630 miner: do not propagate exceptions through dtor (moneromooo-monero)
2e2139ff epee: do not propagate exception through dtor (moneromooo-monero)
0749a8bd db_lmdb: do not propagate exceptions in dtor (moneromooo-monero)
1b0afeeb wallet_rpc_server: exit cleanly on unhandled exceptions (moneromooo-monero)
418a9936 unit_tests: catch unhandled exceptions (moneromooo-monero)
ea7f9543 threadpool: do not propagate exceptions through the dtor (moneromooo-monero)
6e855422 gen_multisig: nice exit on unhandled exception (moneromooo-monero)
53df2deb db_lmdb: catch error in mdb_stat calls during migration (moneromooo-monero)
e67016dd blockchain_blackball: catch failure to commit db transaction (moneromooo-monero)
661439f4 mlog: don't remove old logs if we failed to rename the current file (moneromooo-monero)
5fdcda50 easylogging++: test for NULL before dereference (moneromooo-monero)
7ece1550 performance_test: fix bad last argument calling add_arg (moneromooo-monero)
a085da32 unit_tests: add check for page size > 0 before dividing (moneromooo-monero)
d8b1ec8b unit_tests: use std::shared_ptr to shut coverity up about leaks (moneromooo-monero)
02563bf4 simplewallet: top level exception catcher to print nicer messages (moneromooo-monero)
c57a65b2 blockchain_blackball: fix shift range for 32 bit archs (moneromooo-monero)
