Support reopening when file is replaced (tail --follow=name)

[charles-dyfis-net]

At present, pytailer does not poll for whether a file's direntry has been replaced, as during log rotation; GNU's version of the tail command does have this functonality.

Add an optional flag to the follow() call to persist in following a file even when that file has been rotated. If this flag is set and no new content is available after a sleep, the directory entry should be checked to determine whether it points to the same inode -- and if a new file replaces the old one, that new file should be opened and all lines from the very top of the file returned.

[nibalizer]

bump

[hiteshd]

bump again. Also willing to help

[six8]

Will accept pull requests. Haven't had a chance to work on this.

[niels-anders]

Exactly how I use pytailer, for following log files that rotate. Any chance this will be picked up some time?