Remove unused imports in macdeploy script
doc: Clarify wording about testing in README.md

Weaken and clarify the wording a bit, it currently implies that we get
more pull requests than we can ever handle which discourages
contribution.
osx: Fix missing dock menu with qt5

Qt5 Removed the qt_mac_set_dock_menu function and left no replacement. It was
later re-added and deprecated for backwards-compatibility.

Qt5.2 adds the non-deprecated QMenu::setAsDockMenu(). Use that when possible.
Merge pull request #4187

d16f6f8 Remove unused imports in macdeploy script (Federico Bond)
Merge pull request #4252

c21c74b osx: Fix missing dock menu with qt5 (Cory Fields)
Merge pull request #4218

4665b1a doc: Clarify wording about testing in README.md (Wladimir J. van der Laan)
Properly initialize CWallet::nTimeFirstKey
Change nTimeFirstKey initialization to regular 0 instead of 0l
Merge branch 'master' of https://github.com/tm314159/bitcoin

rebased from upstream.