Improvements for translation-tool.pl

After several tests of 3bfe97e4 I found that library does not support:
- proper using characters stored as \uXXXX so then translated files have values without \u
- keys with spaces such as `jenkins\ title` is not supported

So then I decided to revert last commit and add a little improvement but still there are problems with
- values which ends with `\` so value is provided as multiline
- lines with more than single `=` character that are already translated