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 (this is typically not PMCs, but could be code wizards)

[jasper]

In [5e56d1891a3eb0640e76983a5579333f2109c825]:

Fix #169

[jasper]

In [0d4e9065a3ee36bdd80fa37c90e025d174b765b7]:

Fix #169