Allow -onlynet=onion to be used

Just an alias for onlynet=tor, but matches the new name
of the proxy option -onion= better.
Add IsReachable(net) function

Allows other parts of the program to query for reachable
status of a network. Similar to IsLimited(net).
Add GetNetworkName function

Returns the network name for an Network enum.
Simplify serialize.h's exception handling

Remove the 'state' and 'exceptmask' from serialize.h's stream implementations,
as well as related methods.

As exceptmask always included 'failbit', and setstate was always called with
bits = failbit, all it did was immediately raise an exception. Get rid of
those variables, and replace the setstate with direct exception throwing
(which also removes some dead code).

As a result, good() is never reached after a failure (there are only 2
calls, one of which is in tests), and can just be replaced by !eof().

fail(), clear(n) and exceptions() are just never called. Delete them.
remove unused class CAddrMan; from db.h
Make CCryptoKeyStore::Unlock check all keys.

CCryptoKeyStore::Unlock has a loop to attempt decrypting each key which
 only executes once, likely due to a simple mistake when the code was
 originally written.

This patch fixes the behavior by making it check all keys. It also adds
 a fatal assertion in the case some decrypt but some do not, since that
 indicates that the wallet is in some kind of really bad state.

This may make unlocking noticeably slower on wallets with many keys.
Dont run full check every time we decrypt wallet.
Add a getutxos command to the p2p protocol. It allows querying of the UTXO set
given a set of outpoints.
build: Fix boost build on some platforms

When the libpath doesn't line up with the value from config.sub, we don't find
the correct path to boost's libs. This adds a hack to try another path before
giving up.

Should close #3219.
[Qt] Revert overviewpage from QFormLayout to QVBoxLayout
gui: remove redundant numTransactions tracking

This number was still tracked even though it's shown nowhere in the UI
anymore. It was originally removed because it didn't match the actual number of
records in the view (which contains outputs, not transactions) thus was
confusing people.
doc: Remove outdated information about boost versions

Bitcoin core should work with any remotely recent boost version
if a proper build environment is present. Remove a confusing comment
from the build documentation.
Add detailed network info to getnetworkinfo RPC

This commit adds per-network information to the
getnetworkinfo RPC call:

- Is the network limited?
- Is the network reachable
- Which proxy is used for this network, if any

Inspired by #2575.
Merge pull request #4605

aa82795 Add detailed network info to getnetworkinfo RPC (Wladimir J. van der Laan)
075cf49 Add GetNetworkName function (Wladimir J. van der Laan)
c91a947 Add IsReachable(net) function (Wladimir J. van der Laan)
60dc8e4 Allow -onlynet=onion to be used (Wladimir J. van der Laan)
qt: Use quint64 for formatServicesStr

`uint64_t` was causing a build error on some systems, as that type is
not known after including just the Qt headers.
Univalue: Do not build JSON escape list at runtime

No need to waste startup time building something that can be done
at compile time.

This also resolves a clang++ warning originally reported in #4714,
univalue/univalue_write.cpp:33:12: warning: array subscript is of type 'char
escapes['"'] = "\\"";
^~~~

etc.
Revert "build: add option for reducing exports"

Revert #4663 for now. It still breaks the pulltester.

This reverts commit 4975ae1722cd8af63eda2f02ef64a98091b6fb58.

Conflicts:
	configure.ac
Merge pull request #4704

54c7df8 build: Fix boost build on some platforms (Cory Fields)
replace int with size_t in stream methods

Thus the read(...) and write(...) methods of all stream classes now have identical parameter lists.
This will bring these classes one step closer to a common interface.
build: add option for reducing exports (v2)

This was committed previously as 4975ae172 and reverted, because the flags were
applied even if the checks didn't pass. This is the same commit, fixed up to
actually disable the functionality when necessary.

Enabled automatically if boost >= 1.49.
See: https://svn.boost.org/trac/boost/ticket/2309

Also, check for a default visibility attribute, so that we can mark future
api functions correctly.