Serialization of uses/if-feature/range values inserts extra space

[andreasjakobik]

When serializing a created model, spaces before/after double quotes in 'uses' and 'if-feature' are inserted. This happens also for ranges that have been split up in several strings.

[andreasjakobik]

Another manifestation of same problem occurs in the following example:

Before preprocessing the node was:

    identity symmetric-key-format {         
       base " key-format-base";     // no space     
       description "Base key-format identity for symmetric keys."; 
     }

After preprocessing the node is:

    identity symmetric-key-format {         
       base " key-format-base ";     // a space is added
       description "Base key-format identity for symmetric keys."; 
     }