Fix linux ifdef.

__linux__ is defined more reliably by Linux systems.  Likewise,
'i386' isn't always defined, but __i386__ (for i386 systems, of
course) is reliably defined.
Fix case of include file.
Fix include path.
Linux still have issues with the shared approach.

So disable it for now.
New Linux configuration.

Based on a patch from 'bank'.
With gcc, build in C++11 mode.

This gets us the stdint types.  Of course, we can also start using
C++11 features as well.

But forces developers to have a semi-recent gcc... I think gcc4.5,
but 4.4 might work.  Earlier versions work if the developer manually
changes the "c++11" here to "c++0x".
Add needed freetype2 include path on Linux.
gnu: switch to both compiling + linking with the c++ compiler.

Removes the need to explicitly specify -lstdc++, which can be
aggravating when you've got a bi-arch system and are using -m32,
for example.
get platformX86UNIX compiling.

Almost certainly broken.  Got the GL API binding stuff working by
simply removing it; we probably have null function pointers now,
but I think almost all this code can be replaced with GLEW anyway.

OpenAL might also be broken similarly.  We can probably just drop
the indirection here.

Events confuse the hell out of me right now.  It seems like the
platform/ interface has been updated often, and platformX86UNIX
has not kept face. Thus there seems to be a bit of duplicate
functionality and probably some routing issues.
Don't build with fmod on Linux.

Temporarily?  Big can of worms, not easy to install.
Linux: add simple missing libraries to build.

"simple" meaning they exist as part of package managers and can
just be installed on the host system.  Maybe the other libraries
exist in the source tree somewhere, and could be used from there.
Simplify typing considerably.

Use only the types from platform/types.h, which are now
cross-platform/compiler.