[Qt] rename In:/Out: to Received/Sent in traffic tab

- collides with In:/Out: used for displaying number of
  connections when translating
Add `-stopafterblockimport` option

Stop after importing blocks. This can be useful for development
and trouble shooting.
sanity: autoconf check for sys/select.h
sanity: add libc/stdlib sanity checks

These are meant to test our back-compat stubs, but they are enabled for all
builds for the sake of consistency.
sanity: hook up sanity checks
Added encryptwallet call to bitrpc.py

This was the only call requiring password input which was still missing. Much useful to avoid leaving a plain text passphrase in the shell log.
Get rid of Params().RPCisTestNet()
Add "chain" to getmininginfo, improve help in getblockchaininfo
Merge pull request #4333

f6984e8 Add "chain" to getmininginfo, improve help in getblockchaininfo (jtimon)
b82b7ec Get rid of Params().RPCisTestNet() (jtimon)
Merge pull request #4346

1569353 Add `-stopafterblockimport` option (Wladimir J. van der Laan)
Merge pull request #4354

7ad720d Added encryptwallet call to bitrpc.py (dllud)
Merge pull request #4339

92a6220 sanity: hook up sanity checks (Cory Fields)
679240d sanity: add libc/stdlib sanity checks (Cory Fields)
11404af sanity: autoconf check for sys/select.h (Cory Fields)
Merge pull request #4334

6763018 [Qt] rename In:/Out: to Received/Sent in traffic tab (Philip Kaufmann)
[Qt] New status bar Unit Display Control and related changes.

- New status bar control shows the current Unit of Display.
  When clicked (left,or right button) it shows a context menu
  that allows the user to switch the current Unit of Display (BTC, mBTC, uBTC)
- Recent Requests and Transaction Table headers are now updated when
  unit of display is changed, because their "Amount" column now displays the
  current unit of display.
- Takes care of issue #3970 Units in transaction export csv file.
- Small refactors for reusability.
- Demo Video https://www.youtube.com/watch?v=wwcr0Yh68go&list=UUG3jF2hgofmLWP0tRPisQAQ
gubatron test