Refer Bug https://bugs.freedesktop.org/show_bug.cgi?id=66985 for the background.
in LO, the numbers and dates which are formatted as text by prepending an apostrophe cannot easily be converted to regular numbers / dates. There is an extension http://extensions.libreoffice.org/extension-center/ct2n-convert-text-to-number-and-dates which already does this. this bug entry proposes to integrate that extension and create an easy to use context menu to warn the user and convert such numbers to number format.
*** This bug has been marked as a duplicate of bug 33962 ***