Redirect user to signature list after signing ICLA

After a user has signed or re-signed an ICLA, redirect them to the list of individual
contributors (currently the Contribute menu nav item). This removes any
confusion dealing with resigning or refilling out the form.
Update non-admin CCLA signature view text.

In the manage profile agreements tab, update the language surrounding viewing
the CCLA signature content. Eventually, this should be changed to view
Organization or view Contributors where the user can view the other members of
that organization instead of the form to update the signature.
Display information about re-signing an ICLA.

When viewing an ICLA, display information surrounding what it means to resign
the ICLA and when it was originally signed.
Remove company column and adjust name display in sigs list

Remove the company column displayed in the table of ICLA signatures.

When viewing the list of ICLA signatures on production, there appear to be some
blank names. Using the first and last name (required fields of the signature)
ensures that it will not be blank.
Change Approved Contributors copy to Contributors.