[feature/migrations] Inject migrator rather than the container.

Some docblocks

PHBB3-9737
Merge branch 'feature/migrations-data' of github.com:EXreaction/phpbb3 into feature/migrations-data

# By Dhruv (19) and others
# Via Nathaniel Guse (3) and others
* 'feature/migrations-data' of github.com:EXreaction/phpbb3: (38 commits)
  [feature/migrations] Use the user class for language handling
  [feature/migrations] Fully revert the removal of the user_msnm field
  [feature/migrations] Revert unrelated change to schema_data.sql
  [ticket/11179] remove extra & in function call
  [ticket/11179] correct start parameter in sphinx search
  [ticket/11179] correct start parameter in native author search
  [ticket/11179] correct start parameter in native keyword search
  [ticket/11179] fix success query path for postgres
  [ticket/11179] fix success query path for mysql
  [ticket/11179] minor fixes
  [ticket/11179] pass start param by reference in postgres
  [ticket/11179] correct start param in author search of postgres
  [ticket/11179] correct start parameter in psql keyword search
  [ticket/11179] pass start param by reference in author search
  [ticket/11179] correct start parameter for author search
  [ticket/11179] use FOUND_ROWS query to re-search with changed start param
  [ticket/11179] pass start parameter by reference
  [ticket/11179] correct the start parameter while retrieving from cache
  [ticket/11179] add search query in case initial one fails
  [ticket/11359] html escape sphinx config data
  ...