fix xobject text extraction and add text fallback in case of missing …

…font

preg_match updated

change project license from GPLv2 to GPLv3 to match TCPDF requirements

rewrite method Page::getText + hotfix

update parser to support content array object

hexadecode - hotfix

support more chars for font name / better hexa element parsing

support for specific date format and spaces escape

quick fix for issue smalot#6

add helpers to read metadata properties