Ref. #34

This PR adds new command kb-macro.repeatPlaybackTillEndOfFile.

This command repeats the playback until the cursor reaches the end of the file.
In detail, the behavior is as follows:

• Perform the playback at least once.
• Perform each playback atomically.
• Stop the repeat if the distance between the cursor and the end of the file didn't decline in a playback.
• The distance is measured mainly using the line count.
• When comparing two distances (before a particular playback and after that), if the line counts are equal, then it compares the character count between the cursor and the end of the line.

This command can be called by the user via Command Palette.
The command name is Repeat Playback Till End of File.