aboutdialog: use just "The Bitcoin developers" as tr()-string

- this ensures our new splash screen and this will share a translatable
  string an remove the need for an additional translation
bitcoin: use static QApplication:: instead of app.
bitcoingui: remove 2 unneeded includes
overviewpage: make some code Qt5 compatible

- that changes will be fine for Qt4 also
Add bitcoin-qt.pro homebrew patch
Update Qt Readme to include HomeBrew setup for OSX
Update Tor.txt for grammar fixes
Merge pull request #2556 from APerson241/master

Some small grammar fixes
Merge pull request #2526 from Diapolo/Qt_misc

Bitcoin-Qt: misc small changes
Reduce number of open LevelDB files to 64
Merge pull request #2557 from sipa/leveldb64

Reduce number of open LevelDB files to 64
Merge pull request #2554 from fanquake/qt-pro-brew-patch

bitcoin-qt.pro Brew patch