Add support for 1904 dates

This commit adds support for dates using the 1904 calendar (starting 1904-01-01 00:00:00).
It also fixes some issues with the dates in 1900 calendar (which now correctly start at 1899-12-30 00:00:00).
Finally, it is now possible to have negative timestamps, representing dates before the base date (and up to 0000-01-01 00:00:00), as per the SpreadsheetML specs. Note that some versions of Excel don't support negative dates...

src/Spout/Reader/XLSX/Manager/OptionsManager.php

@@ -20,6 +20,7 @@ class OptionsManager extends OptionsManagerAbstract
             Options::TEMP_FOLDER,
             Options::SHOULD_FORMAT_DATES,
             Options::SHOULD_PRESERVE_EMPTY_ROWS,
+            Options::SHOULD_USE_1904_DATES,
         ];
     }
 
@@ -31,5 +32,6 @@ class OptionsManager extends OptionsManagerAbstract
         $this->setOption(Options::TEMP_FOLDER, sys_get_temp_dir());
         $this->setOption(Options::SHOULD_FORMAT_DATES, false);
         $this->setOption(Options::SHOULD_PRESERVE_EMPTY_ROWS, false);
+        $this->setOption(Options::SHOULD_USE_1904_DATES, false);
     }
 }