cbcollect_info: Fails on Win 7 if cbstats execution fails

When running cbcollect_info from 3.0.0-713 on Windows, it fails (and produces no zip file) if it fails to run one of it's commands. As cbcollect_info is our primary diagnostic tool I'm marking this as a blocker.

Full output below:

C:\Program Files\Couchbase\Server>type VERSION.txt
3.0.0-713

C:\Program Files\Couchbase\Server\bin>cbcollect_info win7_cb300.zip
System information (systeminfo) - OK
Computer system (wmic computersystem) - OK
Computer OS (wmic os) - OK
Service list (wmic service where state="running" GET caption, name, state) - OK
Process list (wmic process) - OK
Process usage (tasklist /V /fo list) - OK
Swap settings (wmic pagefile) - OK
Disk partition (wmic partition) - OK
Disk volumes (wmic volume) - OK
Network configuration (ipconfig /all) - OK
Taking sample 2 after 10.000000 seconds -
OK
Network status (netstat -ano) - OK
Network routing table (netstat -rn) - OK
Arp cache (arp -a) - OK
Network Interface Controller (wmic nic) - OK
Network Adapter (wmic nicconfig) - OK
Active network connection (wmic netuse) - OK
Protocols (wmic netprotocol) - OK
Cache memory (wmic memcache) - OK
Physical memory (wmic memphysical) - OK
Physical memory chip info (wmic memorychip) - OK
Local storage devices (wmic logicaldisk) - OK
Checking for server guts in C:\Program Files\Couchbase\Server\var\lib\couchbase\initargs...
product diag header () - OK
Database directory structure (dir /s "C:\Program Files\Couchbase\Server\var\lib\couchbase\data") - OK
Index directory structure (dir /s "C:\Program Files\Couchbase\Server\var\lib\couchbase\data") - OK
Version file (type "."\..\VERSION.txt) - OK
Manifest file (type "."\..\manifest.txt) - Exit code 1
Manifest file (type "."\..\manifest.xml) - Exit code 1
Couchbase config () - OK
Memcached logs (cd "c:\Program Files\Couchbase\Server\var\lib\couchbase\logs" && for /f %a IN ('dir /od /b memcached.log.*') do type %a) - OK
Ini files (c:/Program Files/Couchbase/Server/bin/../etc/couchdb/default.ini) (type "c:\Program Files\Couchbase\Server\bin\..\etc\couchdb\default.ini") - OK
Ini files (c:/Program Files/Couchbase/Server/bin/../etc/couchdb/local.ini) (type "c:\Program Files\Couchbase\Server\bin\..\etc\couchdb\local.ini") - OK
Ini files (c:/Program Files/Couchbase/Server/bin/../etc/couchdb/default.d/geocouch.ini) (type "c:\Program Files\Couchbase\Server\bin\..\etc\couchdb\default.d\ge
ocouch.ini") - OK
Ini files (c:/Program Files/Couchbase/Server/bin/../etc/couchdb/default.d/capi.ini) (type "c:\Program Files\Couchbase\Server\bin\..\etc\couchdb\default.d\capi.i
ni") - OK
Ini files (c:/Program Files/Couchbase/Server/bin/../etc/runtime.ini) (type "c:\Program Files\Couchbase\Server\bin\..\etc\runtime.ini") - OK
couchbase diags (curl -sS -u :***** http://127.0.0.1:8091/diag?noLogs=1) - OK
couchbase logs (debug) (cbbrowse_logs debug) - OK
couchbase logs (info) (cbbrowse_logs info) - OK
couchbase logs (error) (cbbrowse_logs error) - OK
couchbase logs (couchdb) (cbbrowse_logs couchdb) - OK
couchbase logs (xdcr) (cbbrowse_logs xdcr) - OK
couchbase logs (xdcr_errors) (cbbrowse_logs xdcr_errors) - OK
couchbase logs (views) (cbbrowse_logs views) - OK
couchbase logs (mapreduce_errors) (cbbrowse_logs mapreduce_errors) - OK
couchbase logs (stats) (cbbrowse_logs stats) - OK
couchbase logs (babysitter) (cbbrowse_logs babysitter) - OK
couchbase logs (ssl_proxy) (cbbrowse_logs ssl_proxy) - OK
couchbase logs (reports) (cbbrowse_logs reports) - OK
couchbase logs (xdcr_trace) (cbbrowse_logs xdcr_trace) - OK
couchbase logs (access) (cbbrowse_logs access) - OK
memcached stats all (['cbstats', '-a', '127.0.0.1:11210', 'all', '-b', '_admin', '-p', 'a4d7aae8ddc2aae22447cb0f64b6b4b0']) - Traceback (most recent call last):

File "cbcollect_info", line 565, in <module>
main()
File "cbcollect_info", line 545, in main
runner.run(task)
File "cbcollect_info", line 127, in run
result = task.execute(fp)
File "cbcollect_info", line 66, in execute
shell = use_shell, env = env)
File "subprocess.pyc", line 679, in _init_
File "subprocess.pyc", line 896, in _execute_child
WindowsError: [Error 2] The system cannot find the file specified

Note: The issue here isn't what cbstats is missing - that is covered by MB-11131. This is covering the fact that cbcollect_info shouldn't fail to produce a zip file if a subcommand fails.