Merge pull request #26 from StackExchange/icmp

Add Remote ICMP support
Ignore non-executable files

fixes #27
Merge branch 'master' of github.com:StackExchange/scollector
Correct executable checking on windows

fixes #27
Always set the downsample

fixes StackExchange/bosun#157
Add warning about go1.3 on windows
Add option to filter response tags if not in request

fixes StackExchange/bosun#161
Use a common interval
Initial metadata support
Fix metadata build on linux
Slightly more resilient linux version check
Windows version and net iface metadata
Specify if we want to add the host tag to metadata
Send metadata each hour
Metadata for windows disk
Explain the purpose of the wait more
Revert to simple os.cpu windows handling

The previous version was incorrect because it did not take into account
timing. However, even if it did it would still be wrong. Between the
time that two points were sent, the counter is still going up. Thus,
the next time it *does* get sent the diff in bosun will be large. Not
sure how to fix.
Store metadata tags as a tagset
Use strings instead
Simpler, sorted collectors list