Memory leaks in IDL parser

[jasper]

IDL parser leaks memory:

• returned object has initial reference count that is too high, so is never released
• yacc was not instructed to release its stack
• temporary items were not all released under successful parse conditions
• temporary items were not released at all under unsuccessful parse conditions

[jasper]

Validation is performed using valgrind under linux

[jasper]

As part of the fixes are in the client header files, applications that explicitly refer to the IDL type library interfaces should recompile.

[jasper]

In [5e56d1891a3eb0640e76983a5579333f2109c825]:

Fix #169

[jasper]

In [0d4e9065a3ee36bdd80fa37c90e025d174b765b7]:

Fix #169