Don't mess with pidfile if it has our pid

If you HUP gmond and you ran it with -p it will reexec itself, keeping its
pid, read the pidfile, find a process with its pid running and exit (so as
to prevent two gmonds running at once).  This isn't correct as it should
just keep running and not do anything with its pidfile.
Merge pull request #57 from sflow/master

Add support for sFlow Nvidia GPU metrics from hsflowd,  and apache workers metrics from mod-sflow
Add missing Perl module config template.
Merge branch 'master' of github.com:ganglia/monitor-core
Fix module name for Perl config.
Fix for

 http://bugzilla.ganglia.info/cgi-bin/bugzilla/show_bug.cgi?id=317
 http://bugzilla.ganglia.info/cgi-bin/bugzilla/show_bug.cgi?id=251
 http://bugzilla.ganglia.info/cgi-bin/bugzilla/show_bug.cgi?id=238

Change disk reporting to double from uint32 which limits disk reporting to
8TB.
Fix #45, as specified in original issue.
APR instead of homegrown, #49
Fix issue #58
gitignore: ignore *~
llist.c: add missing include for strlen and strncmp.
gmetad: add missing include for read, write and close.
format strings: apply gcc format string attributes and fix the issues.
Merge pull request #59 from saaros/cleanup

Fix format strings and missing includes
gmetad: http support for interactive protocol.

If the interactive query begins with "GET " and ends with " HTTP/1.0"
or " HTTP/1.1" send the response with a HTTP header and do not send a
full XML dump in case there are no matches.  The behavior for existing
interactive protocol does not change.
Merge pull request #60 from saaros/gmetad_http

gmetad: http support for interactive protocol.
Add missing gmond_pkts_sent_failed metric
Sent metadata pkts should inc PKTS_SENT_ALL
Merge pull request #61 from satterly/bug/modgstatus

Minor bugfixes to Ganglia status module
Enable status module for testing as per pull request #61