FIX: Order Cancel/Replace Request and Order Cancel Reject

Signed-off-by: Marat Stanichenko <mstanichenko@gmail.com>
FIX: OrigClOrdID field is added

Such a FIX field is used to identify the order which is
being cancelled or replaced

Signed-off-by: Marat Stanichenko <mstanichenko@gmail.com>
FIX: Increase header and body buffer's size

So far we haven't developed a reliable algorithm to obtain
header or body buffer's size. Current values are not enough
for such messages as Order Cancel/Replace

Signed-off-by: Marat Stanichenko <mstanichenko@gmail.com>
FAST orderbook: set glasks and glbids to NULL explicitly

Once a particular order book is finalized (ob_fini() is called)
we must not refer to internal structures anymore as they are
released. Hence ob_init() is to make sure that internal structures
are initialized before a user is allowed to refer to them.

Otherwise we are exposed to illegal memory access:

ob_fini();
ob_init();

refer to glasks/glbids will lead to SIGSEGV

Signed-off-by: Marat Stanichenko <mstanichenko@gmail.com>
Merge pull request #35 from mstanichenko/mstanichenko

FIX and FAST updates
include extra libraries as run-time dependencies of libtrading.so
fix_session_cfg_new: function to construct a fix configuration.

This kind of function is helpful when writing bindings to libtrading
from other languages where it's easier to treat C structs as opaque
pointers.
Merge pull request #36 from StefanKarpinski/sk/Makefile

include extra libraries as run-time dependencies of libtrading.so
Merge pull request #37 from StefanKarpinski/sk/fix_session_cfg_new

fix_session_cfg_new: function to construct a fix configuration.