If a new directory is found in incoming but the move operation to
processing failed for some reason, the timestamp and username
directories (and potentially some partially moved data?) would remain
in processing. To prevent confusion about those "incomplete" transfer
candidates they are moved to the "ERROR" location.

Refers to #18

Refers to #18, #29

Refers to #18, #28, #29

Refers to #29

Refers to #28

Refers to #28

Refers to #28

Those objects are not meant to be instantiated directly but only using
the Deserialize() methods which takes care of creating a new object in
case deserializing fails for the status class.

This way the value is directly visible in the code where the property is
created, improving readability. Setting defaults in the constructor is
therefore not necessary any more.

Refers to #29

Refers to #18, #28

Refers to #29

Refers to #29

Refers to #29

Refers to #29

Refers to #29

Again, no functional changes in this commit!

Refers to #29

Plus, group them in a logical sequence instead of a type-specific one by
following the order being used in the new example files.

This commit should not introduce any functional changes!

Refers to #29

One file ("config.common.xml") containing site-global configuration
settings, the other one (the file name equals the host name with a
".xml" suffix) containing host-specific settings.

Both files use the same syntax and may contain the same setting
attributes with the host-specific one having priority over the
site-global one.

Refers to #18

They are already set by the XmlSerializer class to the default value of
the corresponding data type.

Do not serialize the status XML if the actual value of ServiceSuspended
and / or LimitReason has not really changed. This effectively prevent
the "heartbeat" value (LastStatusUpdate) from being updated once per
AutoTx timer cycle.

Closes #19

Refers to #26

Having the total progress is much more useful than for the individual
files, especially for transfers with many files.

Closes #26

All projects (and namespaces) should start with an "ATx" prefix, having
a capital "AT" and a lowercase "x".