Handling of large file being written to the watched folder

[nkhalasi]

When large files are being written into a watched folder over some network, there is a possiblity that a partial file is received for processing in the consumer.

There are multiple ways to handle this, but the easiest to ensure that the file's modified timestamp does not change for more than n seconds (e.g. 5 secs) and then send the event over the channel for processing.