Prepare dtrace_isa.c for build

- Tidy up header file inclusions
- Replace curcpu with cpu_number()
- Fix argument of dtrace_getreg
- Tweak for gcc 4.8

Note that the file is still not buildable.
Mark a variable __diagused
Remove unused variables.
Fix wrong variable name, PR bin/48647 from Jim Bernard.
Make db_validate_address compile under 4.8
Remove unused variable
no NaN tests for vax
Misc cosmetic changes to reduce diffs from other m68k ports.

- replace magic numbers with macro via genassym.cf
- include opt_fpu_emulate.h at the top
- use C-style comments
- add register '%' prefix in comments
- sync several comments
- indent adjustments etc.

No text binary changes. (only .global _KERNEL_OPT_FPU_EMULATE is moved)
Hide unused variables in #ifdef FIXME
Fix a bug found by gcc 4.8
Remove unused variables
Kill the "throw()" on a forward declaration for posix_memalign (it does
not match our base declaration and may cause warnings).
Ok: joerg
Restore lost break.
add NETWALKER_INSTALL
Bring over the standalone netpgpverify sources from
pkgsrc/security/netpgpverify.

No functional change.
Add the config.h file as part of the reachover infrastructure
Clean up the reachover infrastructure - the programs now live under the
bin subdirectory
Move the netpgp directory (for the executable) under the bin reachover
directory
Install the binary in the correct location
Move netpgpkeys into the correct place in the reachover insfrastructure