CLEANUP: assorted typo fixes in the code and comments

This is 32nd iteration of typo fixes
diff --git a/src/clock.c b/src/clock.c
index bdbe3cc..eac4251 100644
--- a/src/clock.c
+++ b/src/clock.c
@@ -348,7 +348,7 @@
 
 /* Collect date and time information before calling poll(). This will be used
  * to count the run time of the past loop and the sleep time of the next poll.
- * It also compares the elasped and cpu times during the activity period to
+ * It also compares the elapsed and cpu times during the activity period to
  * estimate the amount of stolen time, which is reported if higher than half
  * a millisecond.
  */