Use Composite Keys for User level tables

[coni2k]

Remove Id field from UserResourcePool, UserElementFieldIndex, UserElementCell tables and use composite keys instead.

Composite key sample;

[Key]
[Column(Order = 1)]
public int LocationID { get; set; }

[Key]
[Column(Order = 2)]
public int DayID { get; set; }

[coni2k]

OData V1-3 doesn't handle composite keys out of the box (or at least it looks like that).
OData V4 could be a solution, wait for #31

[coni2k]

This was solved without upgrading to OData V4, by using a code from the following project;
http://aspnet.codeplex.com/SourceControl/changeset/view/9cb7243bd9fe3b2df484bf2409af943f39533588#Samples/WebApi/ODataCompositeKeySample/ReadMe.txt

It has a custom routing convention class, which worked fine. The good part is that userId doesn't have to be send to the server. It's only asking for the other key and completes the action.