Escape double quotes in R export
Revert "Escape double quotes in R export"

This reverts commit 63a098b3f46b5bb2ffa0a158d842bdc4e1e77627.
Fixed issue #7915: Export to R -> Bug with answers containing double quotes
Dev escape double quotes in R export
Fixed issue: Wrong hint for Rank questions
Merge pull request #90 from jbinard/master

Fixed issue #7915: Export to R -> Bug with answers containing double quotes
Merge pull request #85 from mfaber/strtotime

New feature: Add php-func strtotime() to EM