Dynamic corridor feature lines

[fcernst]

1. When the user toggles the check box here in Corridor Properties to connect and create specific corridor feature lines, please have them enabled to their extracted state so the user doesn't have to go through the extra step of extracting them after creating them here. 
2. Please have these corridor feature lines be dynamic in both directions, causal and reactive, instead of just simply reactive as they are now.
3. Allow all of the feature line editing tools to be used on these corridor feature lines, and allow grip editing of these feature lines.
4. Horizontal alignments and design Profiles will be automatically associated with the corridor feature lines.
5. "Last change/edit priniciples" apply between the alignments, profiles and corridor feature lines. 

• If a PI is added/deleted to the feature line, then it is added/deleted to the profile and alignment.
• If a PI or curve is added/deleted to the Alignment and/or design Profile, then they are added/deleted to the feature line.
• If feature line grades are directly edited, then the design Profile is updated.
• If the design Profile grades are edited, then the feature line is updated.

1. Have a toggle box to check if  the user wants the corridor feature line alignments to be stationed with corridor Centerline stationing, or their own respective feature line alignment stationing, with the ability to easily toggle back and forth between the two stationing conventions. This will help users who have to show gutter flowline stationing for their municipal review process.