Fix Issue 12114
buildNormalizedPath shouldn't normalize current path to empty string
Added unittests (not tested on windows platform)
Doc update
code style (braces) and !is comparison
Spaces between "=="
Spaces between parenthesis
Added tests & changed windows paths to backquoted strings
Merge pull request #2791 from CromFr/issue_12114

Fix Issue 12114 - buildNormalizedPath returns null instead of "."