Fixed bootloader on AIX for loading libpython.

On AIX the define _ALL_SOURCE must be set in order for the dlopen()
flag RTLD_MEMBER to be defined. This flag is necessary to load a shared
object from an archive.

Also, the special format /path/to/archive.a(archive.so) must be used
to reference the shared object.

This fixes ticket 1044 'AIX support broken in version 2.1'.
Added comment about define _ALL_SOURCE for AIX.
Merge pull request #106 from martingd/bug/1044-aix-broken-in-2.1

Issue #1044: Fix bootloader on AIX for loading libpython.

On AIX the define _ALL_SOURCE must be set in order for the dlopen()
flag RTLD_MEMBER to be defined. This flag is necessary to load a shared
object from an archive.

Also, the special format /path/to/archive.a(archive.so) must be used
to reference the shared object.

This fixes ticket 1044 'AIX support broken in version 2.1'.