Removed usage of the opaque png info_ptr struct.

The info_ptr structure should not be used, this has been in the png
documentation since at least July 2000.

Hopefully this mantains the same functionality, but in a way that will
compile with the newest versions of libpng.
Fix previous commit so that it doesn't break the build with libpng v12.0
Use png_bytep instead of png_bytepp for the iCCP profile

As suggested by Andrew Ruder in https://github.com/mono/libgdiplus/pull/3
to avoid storing the profile pointer in an undefined memory location.
Partial implementation of BitBlt from gdi32.dll
tidy code a little
Merge pull request #8 from knocte/fix_build_with_libpng15

Fix build with libpng15
Merge pull request #9 from wtfrank/bitblt

Partial implementation of BitBlt from gdi32.dll
Use FreeType macros for tttables.h inclusion

As of FreeType 2.1.6 (November 2003), using #include to include Freetype libraries directly is not supported.

This has come to a head, as in FreeType 2.5.0, the location of headers has been moved around, breaking building of libgdiplus.

This slight change uses the "official" way to include the required header file, without breaking building on older versions of the library.
Merge pull request #14 from directhex/master

Use FreeType macros for tttables.h inclusion