[ADD] live from the 'Schwarzwaldbahn': db:backup, db:restore
      * added XQuery db:backup, db:restore functionality
      * re-worked XQUF module write-lock handling
Merge branch 'xq-backup-restore-squashed' of https://github.com/LukasK/basex
[MIN] Save actions: remove whitespaces
[ADD] XQuery Module: db:backup, db:restore
[MIN] Allow hiding of field names in constructors (allow "this."...)
[MOD] XQuery: db:drop is executed before db:create again
[ADD] XQuery, Database Module: drop-backup, alter, copy. #870
[FIX] XQuery: Perm=NONE: no permission to resolve file paths
[FIX] Commands, RESTORE: drop old database before restoring new one
[MIN] XQuery, RESTXQ: fixes, better error feedback
[MOD] XQuery: Little Gauss (partial sum) calculation
[FIX] Client/Server: suppress/enforce serialization of XML entities
[ADD] Issue #873: support for both updates and returned items #873
[ADD] Commands: new concurrency test
Merge branch 'master' into issue873
[FIX] XQuery: include context item declaration in locking check
Merge branch 'master' into issue873
[DEL] XQuery/Core: Lock downgrading removed (to be added again)
[MOD] XQuery: optimize detection of updating queries
[MOD] XQuery: refactoring of query resources (preparing #878)