Write a bunch of module documentation.

This commit adds or improves the module-level documenation for:

  buffers.c circuitstats.c command.c connection_edge.c control.c
  cpuworker.c crypto_curve25519.c crypto_curve25519.h
  crypto_ed25519.c crypto_format.c dircollate.c dirserv.c dns.c
  dns_structs.h fp_pair.c geoip.c hibernate.c keypin.c ntmain.c
  onion.c onion_fast.c onion_ntor.c onion_tap.c periodic.c
  protover.c protover.h reasons.c rephist.c replaycache.c
  routerlist.c routerparse.c routerset.c statefile.c status.c
  tor_main.c workqueue.c

In particular, I've tried to explain (for each documented module)
what each module does, what's in it, what the big idea is, why it
belongs in Tor, and who calls it.  In a few cases, I've added TODO
notes about refactoring opportunities.

I've also renamed an argument, and fixed a few DOCDOC comments.

1 files changed, 6 insertions, 0 deletions

diff --git a/src/or/reasons.c b/src/or/reasons.c
index 36921cafcd..a1566e2299 100644
--- a/src/or/reasons.c
+++ b/src/or/reasons.c
@@ -6,6 +6,12 @@
  * \file reasons.c
  * \brief Convert circuit, stream, and orconn error reasons to and/or from
  * strings and errno values.
+ *
+ * This module is just a bunch of functions full of case statements that
+ * convert from one representation of our error codes to another. These are
+ * mainly used in generating log messages, in sending messages to the
+ * controller in control.c, and in converting errors from one protocol layer
+ * to another.
  **/
 
 #include "or.h"