In certain cases Bintray may return errors like `invalid version a.b.c` for
specific tasks. This probably happens because we now running package uploading in
parallel.
Retrying upload one more time should fix the problem.
* Move package building/uploading implementation from config to a separate script.
* Implement new tag '%ci:no-build' to allow immediately stop build with status 'passed'.
%ci:no-build
Keep bare minimum of scripts & configuration files for CI.
Set Travis target language to generic, remove 'Gemfile' and
'Rakefile' since we building *.deb packages and not ruby ones.
Code that determining changes in git repository is reimplemented
in bash.
Disabled packages are excluded from CI tracking as they frequently
cause errors.
Leonid Plyushch