Added auto-complete to "give" ConCommand

[saul]

Auto-completion has been added to the give ConCommand as it exists in L4D2. Classnames that begin with item_ and weapon_ are added to the autocomplete. The classname prefixes are customisable via the s_pEntityPrefixes array in client.cpp.

To get all entity factory class names, the actual factory dictionary has been exposed on the IEntityFactoryDictionary interface (added GetFactoryDictionary method, hence the util.cpp/util.h changes)

In addition, un-necessary sv_cheats->GetBool() == true checks have been removed from the following ConCommands due to them having the FCVAR_CHEAT flag:

• fov (added FCVAR_CHEAT flag)
• give (added FCVAR_CHEAT flag)
• noclip
• god
• setpos
• setang
• setpos_exact
• setang_exact
• notarget
• hurtme

[JoeLudwig]

Instead of taking this pull request we're going to encourage people to pull directly from your repo.