8 string references to 'base_url'

calendar_display_schedule_staff_page in modules/calendar/calendar.module
This page (primarily meant for students) is for quickly finding your advisor or professor or whomever, and finding their link to schedule an appointment with them.
calendar_display_user_appointment_settings_page in modules/calendar/calendar.module
This page is where the user can configure their various appointment settings (like when they offer them)
DatabaseHandler::db_error in classes/DatabaseHandler.php
Draw out the error onto the screen.
engagements_create_new_tracking_img_url in modules/engagements/engagements.module
Generates a URL to our tracking pixel, based on the cid included.
engagements_handle_incoming_sms in modules/engagements/engagements.module
This catches incoming sms messages from POST, but can also be used by our "sms_get_all_messages" function, but it is also used by the sms_get_all_messages to save/update information.
engagements_imap_get_all_received_messages in modules/engagements/engagements.module
Connect to our imap server, download all received messages from students (or others). We will then delete them, so they don't get read twice.
fp_render_menu_item in includes/theme.inc
_fp_error_handler in includes/misc.inc
This is our custom error handler, which will intercept PHP warnings, notices, etc, and let us display them, log them, etc.