Only if libc reports errno 95 Operation not supported the method
should return that extended attributes are not supported. Also
add a debug information about the result of the call to get further
information in the log file
A speciality of the rsync tool is that it behaves differently
if the given source_dir ends with a '/' or not. If it ends
with a slash the data structure below will be synced to the
target_dir. If it does not end with a slash the source_dir
and its contents are synced to the target_dir. For example:
source
└── some_data
1. $ rsync -a source target
target
└── source
└── some_data
2. $ rsync -a source/ target
target
└── some_data
The parameter force_trailing_slash in the DataSync::sync_data
method can be used to make sure rsync behaves like shown in
the second case. This Fixes#1786
The method target_supports_extended_attributes() checks if the
sync target directory supports extended filesystem attributes.
The method is called on sync_data() and will remove the -X / -A
options if provided. A warning message is issued to the caller
if the rsync option list has changed because of the underlaying
filesystem limitations
