Refs codership/mysql-wsrep#33 - change const initialization to assignment to follow the genral style of the file.

Make sure that thd uses the same method to begin and end
OSU operation.

Refs codership/mysql-features#33 - this fixes a bug where wsrep_start_position_update() would pass local_uuid and local_seqno to wsrep_sst_received() instead of real, submitted position.

Sidno initialization was skipped in wsrep_sst_received() if the
received position matched to current position. However, sidno
initialization must be done every time server is started to
add inverted group uuid into sidno map.

  1. factored XID-related functions to a separate wsrep_xid.cc unit.
  2. refactored them to take refrences instead of pointers where appropriate
  3. implemented wsrep_get/set_SE_position to take wsrep_uuid_t and wsrep_seqno_t instead of XID
  4. call wsrep_set_SE_position() in wsrep_sst_received() to reinitialize SE checkpoint after SST was received, avoid assert() in setting code by first checking current position.

The following FLUSH commands are now executed under total
order isolation:
* FLUSH DES_KEY_FILE
* FLUSH HOSTS
* FLUSH PRIVILEGES
* FLUSH QUERY CACHE
* FLUSH STATUS
* FLUSH USER_RESOURCES

refs codership/mysql-wsrep#53 - fencing LOAD DATA splitting related commit to not happen with ALTER processing

Refs #25 - made sure signals that may be set to ignored in mysqld were set to default in the child process.

Going more MTR-friendly - for SST prefer to use mysql client, mysqldump and my_print_defaults from the local build tree.

refs #7 - merged fix from 5.5 branch. However, 5.6 branch has not (yet) surfaced similar applier hang as 5.5

On Windows, the files get checked out with CRLF thanks
to .gitattributes.

on REPAIR don't do table-specific stuff for views
(because even if the view has a temp table opened for it,
it's not opened all the way down the engine. In particular,
Aria crashes in maria_status() because MARIA_HA* info - that is
table->table->file->file - is NULL)

initializers.

c99 style for assigning structure members

modified:
  tabxml.cpp
added:
  xml_html.test
  xml_html.result
  beers.xml
  coffee.htm

- Fix MDEV-7935 by suppressing error resetting code in delete_or_rename_table.
  However, the issue is that this code was added because without it an assertion
  was raised in some cases. Unfortunately I can't remember what were these cases.
  Therefore fixing it in this case will perhaps make a new crash happening on another cases.
modified:
  ha_connect.cc

- Add the UDF Json_Array_Delete.
modified:
  jsonudf.cpp