Slashes Fix

Replace \ with /. Helpful to use sprintf, compose etc.

Some functions (e.g. compose, sprintf, fprintf) use the backward slash ('\') as escape character; therefore, any format specifier containing a backward slash result into error (Warning: Escaped character '\%' is not valid.). This function simply change any backward to forward slash, coping with the issue.
e.g. sprintf(slashes_fix(formatSpec),txt)