fix bison warnings (clash <NONE> != <>)
.gitignore ninja files
MDEV-6107 merge default_tmp_storage_engine

Adapt default_tmp_storage_engine implementation from mysql-5.6
New feature (as compared to 5.6), default_tmp_storage_engine=NULL
means that temporary tables will use default_storage_engine value.
This makes the behavior backward compatible.
Fixed test failure introduced by adding a new dynamic
configuration variable innodb_compression_algorithm.
Removed unnecessary test for removed configuration
variable.
Merge branch '10.1' of github.com:MariaDB/server into 10.1
MDEV-4549 [PATCH] Clean up code working with ACL tables

enum values to index different ACL tables, instead of hard-coded numbers
(even different in diffent functions). Also factor out TABLE_LIST
initialization into a separate function.