Trim tokenized strings in websocket namespace

Issue: SPR-11307
Fixed a typo in RequestMappingHandlerMapping.java
Add explanation for the special 'default' profile

Better integrated explanation of the 'default' profile with both XML
and Java config examples showing the same thing.

Issue: SPR-11256
Fix typo in documentation

Issue: SPR-11301
Polish explanation of the 'default' profile

Issue: SPR-11256