making FAM a required dependency

[James Willcox <jwillcox cs indiana edu>]

Hi all,

gnome-vfs supports the monitoring of local files through FAM.  This is a
great feature, but currently it's not one we can depend on, since FAM
support is optional.  Consequently, if you want things to work as
expected, you have to handle the situation where monitoring isn't
supported by implementing your own monitoring stuff.  I see at least 2
ways to fix this problem.

1)  Make FAM a required dependency for gnome-vfs

2)  Implement a fallback monitoring impl. in gnome-vfs when FAM isn't
available.  (only for local files)

IMHO, 1) is the best solution, assuming that FAM works on all the
platforms we plan to support.

Thanks,
James