update sys_vars.innodb_compression_algorithm_basic to pass

it checked that the default is lz4. Which only worked on systems that
had lz4 and did not have lzo. Now it checks for the default to be zlib,
which works on systems that has neither lz4 or lzo. Like our package
builders in buildbot. This is intentional, we don't want introduce
additional dependencies (lz4, lzo) for our packages just yet.
This can (and will) be reconsidered, and this test can (and will)
be updated again.
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
remove unused sql/examples