release version 3.3.4

bump version number

fix debian prerm script (arangodb#4674)

bump version number

Merge branch '3.2' of https://github.com/arangodb/arangodb into 3.2.11.5

clean up after single delete markers (arangodb#4607)

update revision

update patch level

Documentation 3.4/rename iresearch files (arangodb#4461)

fix size