Finish Release-0.7.2

- Fixed most issues identified by scrutinizer.
Splitted the Str::separated() function to reduce the complexity of the functions.
Splitted the Str::truncate() function to reduce its complexity.
Renamed the Traversor class to Traverser.
Modified the traverser docblocks.
Allow for direct modification of the values of the given array in the Traverser class passing the value by reference.
Add a comment to clarify how to unset values of the array in the traverser.
Updated composer.phar
Formatted code.
Reformatted code to comply more strictly to the PSR-2 code style guide.
Use the Traverser in the Str::separated() transformations and get rid of the switch.
Added a comment to explain why we distinguish ucwords while applying the transformations in Str::separated() function.
Match the branch aliases so that the badge appears correct.
Further splitted the Str::truncateHtml() to reduce its complexity.
Added the Flag class to handle bitwise flag operations.
Added a return description to the Str::match() function.
Fixed error on Flag tests.
Added a method to the TestCase class to get a non-public property value from an object directly through reflection.
Added the PropertyAccessible class.
Added the Flag class to the README Contents section.