Fix compilation warnings for x86 platform.

Fix warnings, reported by C++ compiler from Visual Studio 2010:
 - `strcpy' was replaced by `strcpy_s'
 - `streamoff', returned by `ifstream.tellg', is converted to `size_t'
   explicitly, cause this value is further used by `malloc', which
   takes `size_t' argument, and size of options file is likely to
   always fit `size_t' range.
Fix compilation warnings for x86_64 platform.

Fix warnings, reported by C++ compiler from Visual Studio 2010:
 - use `site_t' to store `strlen' result.
Merge pull request #3 from aleffnull/master

Fix compilation warnings