Explicitly store CStrings so the compiler won't trash them.
Affects GDC 4.8/2.062 when using -Os, -O1 or higher.
Revert "Explicitly store CStrings so the compiler won't trash them."

This reverts commit f923365bd132d999636632ec676c85cab8cfac8f.
Store a reference to the Font object used by Text. This should
actually fix the GDC optimization issue.
-Cast in and out of const for Font reference.
-Re-add stored string pointer, storing as void* to not waste memory
 if both string and dstring are used.
Can cast implicitly to void*
Merge pull request #16 from aubade/master

Fixed GDC Crashes involving Font and Text.