job opening, job requirement, and store updates

- NOTE: current database sql file is: AES_SQL_Query_Iter3-v1.sql
- renamed Job_ID to JobOpening_ID in JobRequirement table to make it
more clear what we are relating...
- removed "unique" from JobRequirement Skill_ID column... for our
purposes, we need to allow multiple skills for multiple job requirements
(for multiple jobs openings...)
- Store_ID column added to JobOpening table (for the sake of time: one
job opening is attached to one store)
- took out JobOpening_ID from Store table for now (because a store might
_have many_ job openings...)
- updated the GetJobOpeningsByStoreID() in AESApplicationService.svc.cs
to reflect the JobOpening_ID change (in the Store table)
- added IStoreService.cs
- added API StoreController.cs
- job openings now specify related store (e.g. Job Opening A is for
Store B)
- added view details of a job opening (from hiring manager's
perspective)