Remove useless dependences

[yyjdelete]

1. Fix build for DynamicLinqWebDocs.
2. Dynamic load System.Data.EntityorEntityFramework as predefined types if it is found.
3. SqlFunctions, SqlSpatialFunctions and DbFunctions(EF6) is also supported.
4. Allow to overwrite keywords.
5. Allow to use FullName of type(_May not works_).
6. System.Data.Entity is always here, so overwrite short name of it with EntityFramework if EntityFramework is found. If System.Data.Entity is needed, FullName of type can be used(_FullName may not works as 5_).
7. Remove usless dependences(System.Data.Entity,JetBrains.Annotations and many others for dnxcore5 and dotnet54).

[StefH]

Thanks for this pull-request, however, I cannot figure out how to create a unit-test to test this change ? Do you have any ideas?