Removed redundant table CommitteeIdeas from database

This table was based on the many-to-many relationship between the tables
Committee and Ideas, which is not the case. Therefore this table has been
dropped and a foriegn key already exists in the table Idea that references
the Committee member that approved this idea.
Edited default value of integer columns

Integer columns if not initialized would have a value of nil,
which would not be usable.They have to have a default value.
Edited the IdeaCommittee relationship

This edits how the relationship was created. It was a HABTM relationship
and after editing it is a one-to-many relationship.
Removes the timestamps from the join tables

remove the timestamps from the joining tables to make the HABTM relationship work.
Fixes the invited-Admin relationship

A minor change in the invited model file.
Edits the accessible attributes of the Comment model
Adds seed.rb file

Adds seeds in the database which can be used by the rake db:seed
command. Some attributes have been made accessible to be able to
create some seeds.
Merge pull request #106 from DevYah/master_modifications

Various Schema fixes, and a seeds file.