Updated FreeImageRe -> v4.1.0

Updated copyright

Settings: fixed displaying values of plugin path

TextWidget supports auto color based on Windows color theme

Replaced debug version of heif.dll by release version

Updated FreeImageRe -> v0.4

Updated FreeImageRe v0.2 -> v0.3

Move settings helpers to Settings class to fix compilation of the thu…

…mbnails library without QWidgets

Improved histogram visualization; fixed hiding histogram on empty ima…

…ge; implemented dynamic histogram update for GIF

Added missing qt binaries to package