Netty Direct Buffer warning fix

When deploying Wildfly 8.x, you'll see this in the server.log:
```
INFO [io.netty.util.internal.PlatformDependent] Your platform does not provide complete low-level API for accessing direct buffers reliably. Unless explicitly requested, heap buffer will always be preferred to av
oid potential system unstability.
```
Following this into netty, here:
https://github.com/netty/netty/blob/master/common/src/main/java/io/netty/util/internal/PlatformDependent.java#L581
Down to here:
https://github.com/netty/netty/blob/netty-4.0.15.Final/common/src/main/java/io/netty/util/internal/PlatformDependent0.java#L82

We need access to sun.misc to see if direct buffers are available.
Update module.xml

Added javassist after inspecting io.netty log messages as "FINE" level after Wildfly startup and seeing additional information from netty requesting javassist for performance.
Update module.xml

Add optional flag to javassist as this is part of Wildfly-core
[WFLY-3898] Speed up LDAP tests - use InMemory partitions for the ApacheDS
WFLY-3876 Porting to IJ 1.2.B4
Merge pull request #6758 from kwart/jbqa-10729-sec-realm-ldap-cache-wfly
Merge pull request #6745 from maeste/WFLY-3876
Merge pull request #6686 from innerverse/patch-1