Add sparkle framework, fixes #268

Note that the updater is not connected yet,
as we dont have an appcast XML at the moment
available.
Disable JSON_DEBUG, else VS complains
Fixed constraintsAdded BOOl in TimerEditView (osx)
Merge branch 'master' of github.com:toggl/toggldesktop
Fix sparkle build (osx)
Add missing Sparkle.pch (osx)
Merge branch 'master' of github.com:toggl/toggldesktop
Duration color is white when running (osx)
Added tooltips to description and duration in timer (osx)
Added new logo to loginView (osx)
Add old Toggl icon for Windows tray
Windows tray icon
Logout in tray menu (win)
Vertically aligned login page textfields (osx)
Merge branch 'master' of github.com:toggl/toggldesktop
Errormessage is selectable (osx), closes #272
Moved forgot password link to errorbox (osx), closes #280
Tray icon wiring (win)
Open in browser and go to support site via lib
Global shortcuts continue TE-s instead of creating new ones, fixes #173 (osx)