Updated JoinManager plan, included initial ManyToMany code

(Probably does not run yet...)
Moved database classes to ufcommon.sys.db

Also added custom manager, that lets us change the table name manually.
Further updates to ManyToMany also
Deleted the old files that have moved
Added TimeOfDayTools.hx to ufcommon
Removed "id" from model, now kept in parent model

Also changed imports to point to new location
Added "var id:SId" to base db.Object

So that we can rely on it being present in our relations classes
Removed custom Manager

I was using it for the purpose of changing the tablename variable, which
was private, but I was able to change that by using haxes @:access() metadata
Updates for ManyToMany and Relationship

Split relationship out into it's own file.

Many small changes to get things compiling - had to stop use of macro
methods because they hard code the table name
Change TimeOfDay typedef to use MediumInt for database storage

We are only slightly too large to use SmallInt (16bit...)