TST: that we do receive IOError if trying to feed broken symlink into path to be monitored by server
BF: do not pass dangling symlinks to  the server to be monitored

This is more of a workaround I guess than a "solution".  Ideally server
should be more clever and allow adding symlinks which eventually might
point to existing file.  But that is probably would be too much complication
for a rare use case.  User on the mailing list informed that then server
does not monitor even other files, thus as a quick workaround -- do not even add dangling links
Merge pull request #369 from yarikoptic/master

Dealing with dangling symlinks -- avoid adding those files to server for monitoring