Alumni, History, and Past Execs Pages

Adds the alumni, history, and past-execs pages.

Updated Exec 2015

Merge pull request #13 from jdreddaway/newexec

Newexec

New Pages

Contains some new pages (/membership and /structure) as well as general updates.

Beginning Members' Section

Merge pull request #10 from jdreddaway/sign_ups

Sign ups