Bug: "Automatic intersection generation failed" error wipes out existing intersections. Subtask: Double- (instead of single) clicking to close a drawn transect.

Double clicking no longer causes the beginning of another transect draw.
Bug: "Automatic intersection generation failed" error wipes out existing intersections. Subtask: on dev: drawing a transect that intersects shorelines but doesn't hit the baseline. (On prod, this just gets stuck in draw mode)

New behavior is if a feature being drawn didn't touch the baseline, it is automatically removed from the edit layer and an alert is shown that the feature does not touch the baseline
Bug: "Automatic intersection generation failed" error wipes out existing intersections. Subtask: Making an edit, updating, clicking back on "Edit" and clicking update again

New behavior is the update transects button is disabled until a transect is added or an existing transect is modified. It is disabled again after sending changes to the server as well as when the edit form is reopened.
Bug: unpressing add transect button when the draw layer is not active
Merge pull request #255 from isuftin/master

Bug squashing for intersections modification workflows