Update mdb port with various fixes.

[jhb]

Summary

• Skip sections in kernel modules without SHF_ALLOC to catch up to r328101.
• Fix autoloading of mdb modules based on FreeBSD kernel modules.
• Add an opensolaris module for opensolaris.ko that includes walkers and commands for avl and nvlist.
• Recognize mchk_calltrap as a trapframe generator.
• Bump PORTVERSION to 0.2.

Submitted by: Jan Kryl <[e-mail]> [2,3]