New upstream release

New Features:

• Added optional fuzzy search. (#100).
• Added support for user-defined styles via custom CSS file. (#268)
• Added support for a basic dark theme (webview only). (#466)
• Added support for high resolution displays. (#111)
• Switched to the CMake build system, support for qmake will be dropped shortly.
• The minimally required Qt version bumped to 5.5.1.
• As the result of above, libappindicator support relies on the built-in Qt implementation.
• Dropped support for Qt WebEngine.
• Removed dependency on Qt Sql by using SQLite directly.

Improvements:

• New tabs now have the search box automatically focused. (#725)
• Added a Retry button to the error box appearing on docset list download failure. (#566)
• Updated welcome page style (includes a Carbon ad banner, which can be disabled in the settings).

Fixed Issues:

• Fixed search for one-character terms. (#698)
• Multiple fixes in the search algorithm. (#603, #650, #677)
• Fixed navigation in some docsets. (#641)
• Fixed portable version not saving docset storage path. (609)
• Many rendering and stability issues fixed by switching to the new Qt WebKit. (#359, #723)

Known Issues:

• Web pages using Fira Sans (e.g., PHP docset) font are rendered in italic. This is an upstream bug with Qt WebKit (#658)