Tests affected: sys_vars.sysvars_server_notembedded

* btr_pcur_move_to_prev_user_rec() removed
* usage of ut_usectime() removed
* other VTQ-related leftovers

Affected tests:
sql_sequence.gtid sql_sequence.replication

Related to ecde299c3b7afd71f16181b6bd0bc8dda31fad5f

Unclosed stmt transaction
TRT failure in inplace

Related to #305

* System fields renamed
* Removed row0ins.ic
* Removed row_update_for_mysql() wrapper

Reverted DICT_TF2_BITS (midenok)

encryption.innodb_lotoftables
encryption.innodb_encryption
funcs_1.is_columns_mysql

innodb.innodb-index-online-fk
innodb.instant_alter_debug
innodb.innodb_skip_innodb_is_tables
sys_vars.sysvars_server_notembedded
main.mysqld--help