[mac] fix build under osx 10.10

  - related issue https://bugreports.qt-project.org/browse/QTBUG-39644
limit ssl debug information output
[mac] suppress compiler warnings under osx
Merge pull request #204 from Chilledheart/develop

several trivial fixes
fixed a bug causing cpu usage even when idle
reduce api requests when tabs are not shown
Merge pull request #205 from haiwen/reduce-api-requests

reduce api requests when tabs are not shown
fixed painting for repo item with long repo names
Build Qt GUI for BSDs by default.
Merge pull request #207 from yason/master

Build Qt GUI for BSDs by default.
[qt5] initial work