Generalize CMake build scripts to be able to
easily add new modules (such as box or feeder).
Move prscfg.{h,c} (confetti general library and
header) from third_party/confetti/ to cfg/ to
simplify the build.
Update configuration file templates and parsing
code to use the new confetti.
Rename cfg/tarantool_cfg.h to cfg/warning.h,
to be able to reuse it in warning.c.
Update tests.

Note: tarantool_feeder is now built in mod/feeder;
tarantool_silverbox is built in mod/silverbox.
Modify .gitignore accordingly.

Addition of required configuration file options broke backward compatibility
(https://bugs.launchpad.net/bugs/708685)

Use the new version of confetti that allows to determine whether array element
is initialized.

Use CMake to:
- Compile tarantool_silverbox, tarantool_feeder.
- enable ./test-run testing out-of-source
- implement Debug/Release configurations
- add ENABLE_BACKTRACE ENABLE_TRACE and HAVE_BFD switches
- support auto-generated targets

	add chkconfig
	add 'reload configuration' command for admin console

	* build tree indexes after full loading
	* save in tree index parsed key (not only tuple)
	* lexicographical order in tree

        allow update of idexed fields
        allow non-contiguous index keys