Gerrit/git commit hook: Detect and fail merge requests when VERSION file not updated

The community has reported an interest in having merge requests rejected when the VERSION file has not been updated.

General version checking logic:

• Use a regex for general version string validation.
• Split string on dot to obtain fields (list = {major, minor, ...}
• Sub-split fields
  • hyphen to separate modifiers
  • string/int boundries:  dev1 => ['dev', '1']
• Individual fields can be examined to compare -dev1, -dev2, -dev3, etc.
• Loop over field data and compare.

Basic error detection:

• Merge request into the master branch:

• • Version string cannot contain "-dev"
  • Version string must increment a single field +1:
    • master contains v1.1.4
    • VERSION file can contain:
      • 1.1.5
      • 1.2.0
      • 2.0[.0]
• The community also requested requiring a version string bump for each code change on (branch != master):

• • 1.1-dev1 => 1.1-dev2 => 1.1-dev3
  • Fail when VERSION string:
    • version_string != 1 + last_version
• Suggestions made based on development workflow, checking non-master merges could be problematic::
  • Behavior would require modifying file VERSION with every submit.
  • We may be able to validate major.minor strings but modifiers like -devXX would be problematic:

• • • Potential problem - requiring a version bump for – devXX branches would serialize merging and often force an extraneous VERSION file edit to accommodate the latest -dev modifier value.