Currently the build without implicitly included precompiled header
is not supported anyway (because Qt MOC source files do not include
stdafx.h, they include plain headers).
So when we decide to support building without implicitly included
precompiled headers we'll have to fix all the headers anyway.
We should count emoji length correctly in cases we have a partial
match for a longer one, but not a full match. If we start reading
the next characters but don't find a full emoji there we need to
have a correct length of a previously found emoji saved already.
