Build improvements and minor fixes.

- Added bootstrap classpath to all javac tasks. Requires the JAVA6_HOME env variable to be set to the Java 6 SDK.
- Enabled parallel compilation on windows.
- Cleaned up compiler flags on windows.
- We now skip any features we don't use from windows.h.
Added autoSizeResult modifier.

It can be applied on an OUT parameter that will receive a count. That count
will then be used as the capacity of the mem<TYPE>Buffer result.

This commit also includes a subset of the changes required for OpenCL support (WIP).
Fixed buffer result type for PointerMapping.DATA.
WIP glfw stuff