Add close dialog button for report submission form -- issue #39
Various content edits

This commit addresses:
* Issue #27
* Issue #40
* Issue #42
Issue 41 - Add sortable list of aldermen to 'Get Involved' page
Issue #43 -- Fix typo in header
Issue #44 - Add active state to navbar

Active class to indicate which page you're currently on
Fix scrollbar issues

Removing margin on map dialog to avoid page overflow, and move dialog
to right side of page to keep from having a scrollbar in the middle of
the page