* Convert to TAP
* Add gh ticket numbers for all test cases
* Get rid of global variables

* Check return codes of libyaml
* Synchronyze check_utf8() logic with libyaml
* Remove analyze_string() - this logic is performed by libyaml
* Add the test cases

* Move test from box suite to app
* Refactor usage of this module
* Use ffi.errno instead of get_errno/set_errno and c module for loading constants

Update the test after #1219 - proper removal of servers

* Don't print information if nothing has changed
* Remove -DENABLE_BUNDLED_XXX options which doesn't work
* Use common names for _DIRS and _LIBRARIES variables

Other changes:

 * Move CJSON sources to libserver to resolve dependency on lua/utils.c

Revised the entire tutorial (file help_en_US.lua):
 * Tested and fixed all sample code snippets.
 * Corrected typos and inconsistent names in screen headers.
 * Updated info about custom delimiters (screen #6).
 * Replaced box.session with fiber (example on screen #10).
 * Swapped screens #11/#12 (fibers/sockets) for smoother story flow.

Removed help-related stub logic (file help.lua).

Updated auto-tests to expect a new output result on help call.

rand() generated the same number after 10k calls

Make more abstract version of key_opts parser to re-use code
for space options.