Patch removing type hinting

The reason for doing this is that it breaks FOF tag implementation, while this only affects a couple of files I removed it for JTable* classes in the whole repository so that we don't use Type Hinting for JTable*. Type hinting may be a good idea but it doesn't work in the real world with developing extensions for Joomla!

The main problem is that FOF uses the JHelperTags(), this is based on JHelper and here the function getRowData has a type Hint of JTable but in this case we have a FOFTable. The type hint makes the JHelperTags() useless for other extensions that are not using JTable directly. 
Why not create a abstract class or interface? has any reason? @rdeutz @mbabker