Add API Docs for lib/spack/llnl (#3982)

* Add API Docs for lib/spack/llnl
* Clean up after previous builds
* Better fix for purging API docs

lib/spack/llnl/util/tty/log.py

@@ -51,7 +51,7 @@ class _SkipWithBlock():
 class keyboard_input(object):
     """Disable canonical input and echo on a stream within a with block.
 
-    Use this with sys.stdin for keyboard input, e.g.:
+    Use this with ``sys.stdin`` for keyboard input, e.g.::
 
         with keyboard_input(sys.stdin):
             r, w, x = select.select([sys.stdin], [], [])
@@ -103,14 +103,16 @@ def __exit__(self, exc_type, exception, traceback):
 class log_output(object):
     """Spawns a daemon that reads from a pipe and writes to a file
 
-    Usage:
+    Usage::
+
         # Spawns the daemon
         with log_output('logfile.txt', 'w') as log_redirection:
            # do things ... output is not redirected
            with log_redirection:
                 # do things ... output will be logged
 
-    or:
+    or::
+
         with log_output('logfile.txt', echo=True) as log_redirection:
            # do things ... output is not redirected
            with log_redirection: