Use latin1 encoding most of the time where default encoding was used
before. Qt 4 assumes latin1 by default while Qt 5 uses utf-8 which is
not what we want.
Use utf-8 encoding in some places where default encoding was used before.
This includes strings coming from RPC.
Fix an issue with SortMode::names[] (filters.cc) where missing comma
between "sort-by-queue" and "sort-by-ratio" resulted in two array entries
being merged into solid "sort-by-queuesort-by-ratio" string and all the
following items being shifted compared to their enum counterparts.