Merge pull request #483 from virtualtam/master

Updated French translation: Full Text Search
Fix typos
Show clang compiler version in "About" window
Gestures: Move static floating-point data members initialization from header to source file
Fix some warnings
Mac-specific: Fix some warnings while compile under MacOS
Mac-specific: Fix popup window calling without modifiers pressed
Mac-specific: Adjust code for Qt5 build
fix icon path
Merge pull request #485 from hyln9/patch-1

fix icon path
better icon path
Update zh_CN.ts
Merge pull request #486 from hyln9/patch-1

better icon path
Merge pull request #487 from hyln9/patch-2

Update zh_CN.ts
Fix typo in Russian translation
Add support for Epwing dictionaries
Full-text search: Fix storing enabled/disabled state (issue #489)
Epwing: Fix external fonts and some headwords
Epwing: Fix audio links, handling some non-standard decoration, refactor headwords retrieving
Epwing: Fix monochrome images, use unicode symbols instead of some extra symbol images