remove unused sql/examples
cmake: prefer INSTALL(PROGRAMS over INSTALL(FILES
cmake cleanup: use MY_CHECK_AND_SET_COMPILER_FLAG.

move MY_CHECK_C_COMPILER_FLAG and MY_CHECK_CXX_COMPILER_FLAG
to a separate file, introduce MY_CHECK_AND_SET_COMPILER_FLAG,
use it where possible.
MDEV-5730 enhance security using special compilation options

-Wl,-z,relro,-z,now
-pie
-fstack-protector --param=ssp-buffer-size=4
-D_FORTIFY_SOURCE=2
MDEV-5730 enhance security using special compilation options

add a comment
MDEV-6393: ANALYZE SELECT crashes ... Don't try printing EXPLAIN if we had an error.
MDEV-6395: Make ANALYZE UPDATE/DELETE handle the degenerate query plans.
MDEV-6398: ANALYZE UPDATE does not populate r_rows

- In print_explain_row(), do not forget to print r_rows.
- Switch Explain_update from using its own counters to re-using
  Table_access_tracker.
- Make ANALYZE UPDATE code structure uniform with ANALYZE DELETE.
Code cleanup, more tests.
MDEV-6392: Change innodb_have_lzo and innodb_have_lz4 as a static
variables and reduce the number of ifdef's
Merge branch '10.1' of github.com:MariaDB/server into 10.1
MDEV-6394: ANALYZE DELETE .. RETURNING fails with ERROR 2027 Malformed packet

- Add support for DELETE .. RETURNING statement in ANALYZE code.
Merge branch '10.1' of github.com:MariaDB/server into 10.1
MDEV-6394: ANALYZE DELETE .. RETURNING fails with ERROR 2027 Malformed packet (now, the code)

Forgot the code
Remove out-of-date comments
MDEV-6376: InnoDB: Assertion failure in thread 139995225970432
in file buf0mtflu.cc line 570.

Analysis: Real timing bug, we should take the mutex before we
try to send those shutdown messages, that would make sure
that threads doing a unfinished flush (they have acquired
this mutex) have time to do their work before we add shutdown
messages to work queue. Currently, we just add those shutdown
messages to work queue and code assumes that at flush, there
is constant number of items to be processed and thus
leading to assertion.
deb hack: don't set CASSANDRA_DEB_FILES unless cassandra can be built
RBR triggers enabling in 10.1
remove a couple of old unused #defines
Increased the version number