frmmain, cleanup and use searchonvt for general search
remove mangatraders (closed #1079)
baseunit, fix searchonvt (fixed #1072)
luastrings, register delete, indexof, indexofname
mangadex, trim last empty uri (fixed #1054)
luabaseunit, register trimstrings
added SKSubs (closed #1046)
mangadex, fix download missing host (fixed #1063)