Exclude when appending

[jneidel]

Given the messages:

ok:
hi

ok:
ho

We get the result:

ok.txt

ok:
hiok:
ho

Expected:

ok:
hi
ho

[jneidel]

Could be achieved simply by not writing the title (in front of the colon) into the body. I.e. it's just the file name.

Otherwise I would have the task in the write function to again detect colon in the first line, which might not even be possible at that point.