Huge Modifications to Profile.php

Now, users can modify each experience individually, as well as add new
experiences. Also added the missing employer name field. Modified the UI
a bit.

Still left to do:
- Profile Picture
- Addition/removal of tags
- Have research reflect the changes I made in experience.
- Make sure that profile controller is checking user's credentials to
see if they have permissions to make the changes they are trying to
make.