clarify LSC 2.1 documentation about createValues and defaultValues

[davidcoutadeur]

Currently, there is a table describing the policy:

<createValues/> 	If no <forceValues/> are specified, no values are read from the source, and a new entry is being added, the attribute will be created with values from <createValues/> 	If no <forceValues/> are specified, and a new entry is being added, the attribute will be created with values from <createValues/> and values from the source
<defaultValues/> 	If no <forceValues/> are specified, no values are read from the source, and the attribute doesn't yet exist in the destination, it is created in an existing entry with values from <defaultValues/> 	If no <forceValues/> are specified, values from <defaultValues/> are added, as well as any source values, to existing destination values 

It is ambiguous and should be clarified:

<createValues/> 	
If: 
* no <forceValues/> are specified, 
* no values are read from the source, and
* a new entry is being added, 
THEN the attribute will be created with values from <createValues/> 

<defaultValues/>
If: 
* no <forceValues/> are specified, 
* no values are read from the source, and 
* the attribute doesn't yet exist in the destination, 
THEN it is created in an existing entry with values from <defaultValues/>

This is to be done in 2.1 documentation only, because in 2.2 this behaviour may be redefined.

[davidcoutadeur]

See also #217

[davidcoutadeur]

For the record, it is fixed in the new sphinx documentation