erts: Set default external enc to use new float scheme

This change was triggered by the OSE float printing function
not working exactly the same way as linux/win32. But it is
also a good one in general as it cuts size in more than half
for floats.
Added support for ENEA OSE

This port has support for both non-smp and smp.

It contains a new way to do io checking in which erts_poll_wait
receives the payload of the polled entity. This has implications
for all linked-in drivers.
ose: Use the swfp when compiling for OSE

The hwfp has been tested as well and seem to work,
but most processors that OSE will run on does not have
a fpu.
ose: Add unsetenv and update to use get_env

Before get_envp was used and this caused the environment
variables to not be accessible in the correct way by
use debug tools.
ose: Add signal debugging macros

To enable just uncomment and all signals going in or out will be
printed to stdout.
ose: Adapt suite for OSE
erts: Make source file info available in lc
ose: Force atleast one async thread for ose

This is needed because a file has to be opened and operated on
in the same process at all times. Using async threads guarantee this.
ose: Convert EFILE_SEEK to unistd seek for gzio

This is needed because OSE does not have the same integers
as unix/win32 for SEEK_ST and friends.
ose: Debug wait__ does receive_fsem instead of wait_fsem

This is done in order to catch rogue signals
ose: Extract signal numbers to common file
ose: lseek() to use SEEK_CUR

This is needed because OSE does not use 1 for SEEK_CUR
ose: Fix stdlib testcases
ose: Change start way to use arguments to beam.smp directly

The old way registered a shell command that needed to be executed. This
way is more flexible as you can also use the lmconf file to set arguments
there.
ose: Add module that allows interaction with any OSE process

The interface of this module is made to be as generic as possible
in order for other IPC mechanisms to mimic it and allow porting of
code between different os:es.
ose: Copied driver_int.h from unix
ose: Change get_envp to ose_get_ppdata for tsd

There is a system limit on the number of ppdata that is available
but that should not be reached, and ppdata is faster than using
get_envp.
ose: Add link conf for gcc 4.4.3
ose: Add eh_frame_hdr section to linker file
ose: Change signal base to registered range