rpc: add `getblockchaininfo` and `getnetworkinfo`

Adds two new info query commands that take over information from
hodge-podge `getinfo`.

Also some new information is added:
- `getblockchaininfo`
  - `chain`: (string) current chain (main, testnet3, regtest)
  - `verificationprogress: (numeric) estimated verification progress
  - `chainwork`
- `getnetworkinfo`
  - `localaddresses`: (array) local addresses, from mapLocalHost (fixes #1734)
qt: periodic translations update
Merge pull request #4127

d387b8e rpc: add `getblockchaininfo` and `getnetworkinfo` (Wladimir J. van der Laan)
build: fix make clean on OSX

Rebased-From: 74df0f5
Rebased-By: Wladimir J. van der Laan <laanwj@gmail.com>
Add missing cs_main lock to VerifyDB

Fixes issue #4139.
[Qt] fix ugly typo in bitcoin.cpp

Closes #4145.

Rebased-By: Wladimir J. van der Laan <laanwj@gmail.com>
Rebased-From: 1e4b083
switch from boost int types to <stdint.h>
json_spirit: #include <stdint.h>
removed a few unnecessary casts
remove unnecessary cast
changed field types in some structures to equivalent unambiguous types

int -> int32_t
unsigned int -> uint32_t
unsigned chat -> uint8_t