Simplify rejections management

[mmagnuski]

🚧 IN PROGRESS

Problems

There are some problems with the current rejections system:

• rejections are managed inconcistently
• there is no single, unified function for adding/removing rejections that would take all the mess into account
• moreover - there seems to be no consensus as to how some things should be handled - most non-obvious cases were just temporary fixes/solutions

Discussion

Handling reject.pre before and after onesec as well as when epoch.distance changes

When onesec has already filled reject.pre:

• clear distance (and fill reject.pre) to signal that it has been performed
  but this is problematic because we loose info on what epoch.distance was used
  epoch.distance can be moved to datainfo but this also generates some inconsistencies: datainfo with epoch field should mean that epoching has been already performed (and is present in the file) and how

  % distance option, epoching should be checking
  % pre - if it is filled, no need to check
  % distance again. If we change distance -->
  % some reworking is needed to save post
  % but clear pre. May be problematic if
  % pre is empty after distance was applied
  % use .distUsed or internal.distUsed ??