Added Update To Add Scheduled Timeframe Column
Added Columns To wpdb->insert

Added column for scheduled timeframe to new quiz and duplicate quiz functions
Added Ability To Edit Scheduled Timeframe

Added jQuery datepicker script. Added options on options tab to allow users to edit scheduled timeframe
Added Column For Scheduled Timeframe
Added Update To Add Column

Added column for the text for the scheduled timeframe
Added Column

Added column to quizzes for the text with the scheduled timeframe
Added Scheduled TimeFrame Text To Functions

Added the timeframe text to the insert calls in the create quiz and duplicate quiz functions
Added Timeframe Text Option

Added ability for user to edit the scheduled timeframe text
Added Ability To Schedule Timeframe

Added the ability to schedule a timeframe that the quiz is active. If a user accesses the quiz outside that timeframe, customized message is displayed instead.
Fixed Missing Semi-Colon
Added Default Text

Added the default "Enter Text Here' to the scheduled timeframe text
Updated Default Timezone

Set the default timezone to the default timezone for the WordPress installation
Updated Timeframe Question
Added Seconds To End Date

Added 86399 to the end date of the scheduled timeframe. This brings the time to 11:59:59 PM on given date
Added Check For Not Scheduling Timeframe

Added an if statement to check if the values are empty. If so, then we are not going to check for timeframe.
Merge pull request #57 from fpcorso/feature/23

Add Schedule Timeframe Feature Resolves #23