Minor tweaks to cell constructor
Remove references to PHP versions < 5.2
Bugfix: Work Item GH-384 - DOM loadHTMLFile() failing with options flags when using PHP < 5.4.0
Additional check that libxml is running at an appropriate version by testing if libxml flag value constants are defined
Fix to getStyle() call for cell object
General: Work Item GH-394 - DefaultValueBinder is too much aggressive when converting string to numeric
Merge branch 'develop' of https://github.com/PHPOffice/PHPExcel into develop