[MIN] XQuery typing, cleanups

[MOD] XQuery, atomic types: pre/post-based instance checks

[MOD] XQuery: item coercion, optimizations & simplifications

[ADD] XQuery, fn:scan-left, fn:scan-right.

[FIX] array:index-where, JUnit tests

[MOD] XQuery, fold & scans: positional arguments

[FIX] Binary Module: fixes

[ADD] XQuery, fn:function-identity. qtspecs#1798

[MOD] XQuery, maps/arrays: getters unified

[MIN] Cleanups

[MIN] XQuery, record coercion: minor optimizations

[FIX] XQuery Update: static update checks. Closes #2409

[FIX] RESTXQ: NullPointerException (cont.). Closes #2408

[MIN] Better variable and function names

[FIX] Store not written at shutdown time. Closes #2407

[MOD] XQuery: util:map-put-at (positional updates)

[MIN] XQuery, map functions: refactorings

[MOD] XQuery records: optimizations for put/remove ops

[MOD] Sets: toArray() → keys()

[MOD] XQuery: compact map for records with fixed entries

make record fn:key-value-pair extensible (#2406)

[MOD] XQuery, compilation: map → record constructor

allow empty names for IOUrl as well (#2405)

[MOD] XQuery, map constructor: assign record types at compile and run…

[MOD] XQuery, HTML serialization: version strings

[FIX] IOContent resources addressing directories. Closes #2404

[MIN] CommandTest: delete exported file

[FIX] CommandTest: file creation moved into sandbox

[MOD] XQuery, records: better type propagation

[MOD] XQuery, lookups: rewrite to (array|map):get