pcp

Significant reworking of the Windows PMDA; highlights include:

• direct PDH library calls from the PMDA.
• pmdawindows is built in both DSO (.dll) and executable format, as on Linux, and the DSO form is installed into pmcd.conf by default.
• no more checked in binaries (the MsVC-built shim code)
• no more shim code, PDH calls are made in-line in the PMDA, the way nature intended.
• fixed a couple of descriptor leaks
• fixed the query caching logic so that each metric fetch results in a maximum of Q_NUMQUERIES fetches from the kernel, rather than a maximum depending on the numpmids in the fetch request.
• dynamic instance domain handling, instead of fixing all indoms with whatever was there at startup
• beginnings of per-process and per-thread metrics, as exported by the Win32 PDH API.