simplify logic in Utils::secureText() by using a lambda
Use mb_strlen/mb_strpos function when manipulating unicode strings
remove temp variable in Strings::endsWith, use mb_substr() instead of substr()
Issue #139 - expose variable bugs in a new view
* view is /variables/
* finds bad variables for the &variable; , $variable , $1$D , {{variable}} patterns
* added to main menu
* factorized search form html in a substemplate
* minor css adjustments ti search form
* + tests for new class AnalyseStrings
Merge pull request #146 from mozfr/Issue139-expose-wrong-variables

Issue #139 - expose variable bugs in a new view
syntax error fix
Issue #139 followup: make sure that regexes for %S and  don't overlap
Fix Issue 115, use only MPL2 licence