Bugfix: DoOepenFile(): NULL termination failed

When pTemp is a LPWSTR type (in the case of UNICODE version),
a NULL termination cannot be done but a memory is destroyed.
Even if it is UNICODE version, pTemp should be a LPSTR type.
DoOepenFile(): file reading size fix

This patch fixes the case which file size increases
between GetFileSize() and ReadfileSize().
Merge pull request #6 from trueroad/bugfix-null-termination

Bugfix: NULL termination