Fix build for Linux

Commit 9d23e845a8ee237d4ee8150bb950c35f7f2e13d3 somehow
got pushed to develop without Gerrit.

This commit fixes the build for Linux by fixing Gecko and
icu.net.dll dependencies

Also revert FW.sln.DotSettings

Change-Id: Iac6fdbc6c46644db742331feb100b132c796d941