Merge branch 'f-query-caching' into 'dev'

CHANGELOG.md

conf/core/cache.ccf

src/main/java/org/caosdb/server/query/Backreference.java

src/main/java/org/caosdb/server/query/Conjunction.java

src/main/java/org/caosdb/server/query/Disjunction.java

...n/java/org/caosdb/server/query/EntityFilterContainer.java

...n/java/org/caosdb/server/query/EntityFilterInterface.java

src/main/java/org/caosdb/server/query/IDFilter.java

src/main/java/org/caosdb/server/query/Negation.java

src/main/java/org/caosdb/server/query/POV.java

src/main/java/org/caosdb/server/query/Query.java

src/main/java/org/caosdb/server/query/RoleFilter.java

src/main/java/org/caosdb/server/query/StoredAt.java

src/main/java/org/caosdb/server/query/SubProperty.java

src/main/java/org/caosdb/server/query/TransactionFilter.java

.../java/org/caosdb/server/transaction/WriteTransaction.java

src/test/java/org/caosdb/server/query/QueryTest.java