Proc Utilities
**************

Helper functions for querying process and system information from the
/proc contents. Fetching information this way provides huge
performance benefits over lookups via system utilities (ps, netstat,
etc). For instance, resolving connections this way cuts the runtime by
around 90% verses the alternatives. These functions may not work on
all platforms (only Linux?).

The method for reading these files (and a little code) are borrowed
from psutil, which was written by Jay Loden, Dave Daeschler, Giampaolo
Rodola’ and is under the BSD license.

**These functions are not being vended to stem users. They may change
in the future, use them at your own risk.**

Changed in version 1.3.0: Dropped the get_* prefix from several
function names. The old names still work, but are deprecated aliases.

**Module Overview:**

   is_available - checks if proc utilities can be used on this system
   system_start_time - unix timestamp for when the system started
   physical_memory - memory available on this system
   cwd - provides the current working directory for a process
   uid - provides the user id a process is running under
   memory_usage - provides the memory usage of a process
   stats - queries statistics about a process
   file_descriptors_used - number of file descriptors used by a process
   connections - provides the connections made by a process

stem.util.proc.Stat(enum)

   Types of data available via the "stats()" function.

   +----------------+-------------------------------------------------+
   | Stat           | Description                                     |
   |================|=================================================|
   | **COMMAND**    | command name under which the process is running |
   +----------------+-------------------------------------------------+
   | **CPU_UTIME**  | total user time spent on the process            |
   +----------------+-------------------------------------------------+
   | **CPU_STIME**  | total system time spent on the process          |
   +----------------+-------------------------------------------------+
   | **START_TIME** | when this process began, in unix time           |
   +----------------+-------------------------------------------------+
