* FIXED: to detect RHEL more precisely
* FIXED: to properly display non-string values in "cid tool env"
* CHANGED: to pack list of project root items, but '.' by default
* CHANGED: "cid tag" without <next_version> now always increments PATCH.
* CHANGED: default packager to generate .package.checksums internally
* CHANGED: default packager ignores only .git*, .hg* and .svn
* CHANGED: to install Docker CE on RHEL & OL7 using CentOS packages
* CHANGED: to install concurrent binary PHP:
* Debian & Ubuntu: 5.6, 7.0 & 7.1 from https://deb.sury.org/
* CentOS, RHEL, OracleLinux: 5.6, 7.0 from SCL
* CHANGED: to install concurrent binary Ruby:
* Debian & Ubuntu: 1.9, 2.0, 2.1, 2.2, 2.3 from Brightbox
* CentOS, RHEL, OracleLinux: 1.9, 2.0, 2.2, 2.3 from SCL
* NEW: added 'major', 'minor' and 'patch' modes for "cid tag"
* NEW: implemented "cid vcs merge/branch/delete/export/taglist/revert"
* NEW: added APT repository "codename fallback" feature
* NEW: added Ubuntu 17.04 Zesty support