some global options bleeding through profiles

[GoogleCodeExporter]

there are some global options that are OS-specific, but show up no matter what 
profile is being used. i guess after all they're called "global" but if we're 
making major arch changes in 3.0 we should remember to try and fix them. 

for example when using a linux profile with vol.py -h:

  --shift=SHIFT         Mac KASLR shift address
  -g KDBG, --kdbg=KDBG  Specify a specific KDBG virtual address
  -k KPCR, --kpcr=KPCR  Specify a specific KPCR address

it would be nice to only show --shift for mac profiles and --kdbg/--kpcr when 
using windows profiles. 

Original issue reported on code.google.com by michael.hale@gmail.com on 4 Feb 2013 at 2:44

• Merged into: #521

[GoogleCodeExporter]

Original comment by michael.hale@gmail.com on 7 Mar 2014 at 9:21

• Added labels: Milestone-3.0.x
• Removed labels: ****

[GoogleCodeExporter]

Original comment by mike.auty@gmail.com on 18 Feb 2015 at 6:54

• Changed state: Duplicate
• Added labels: ****
• Removed labels: ****