Spelling fixes

Spelling fixes in comments and docs, provided by
Kjartan Maraas in bug 657336.

tests/memchunks.c

@@ -253,7 +253,7 @@ old_mem_chunk_alloc (GMemChunk *mem_chunk)
        *  (ie marked to be destroyed).
        * We check to see if all of the segments on the free list that
        *  reference this area have been removed. This occurs when
-       *  the ammount of free memory is less than the allocatable size.
+       *  the amount of free memory is less than the allocatable size.
        * If the chunk should be freed, then we place it in the "free_mem_area".
        * This is so we make sure not to free the mem area here and then
        *  allocate it again a few lines down.

tests/threadpool-test.c

@@ -11,7 +11,7 @@
 #define WAIT                5    /* seconds */
 #define MAX_THREADS         10
 
-/* if > 0 the test will run continously (since the test ends when
+/* if > 0 the test will run continuously (since the test ends when
  * thread count is 0), if -1 it means no limit to unused threads
  * if 0 then no unused threads are possible */
 #define MAX_UNUSED_THREADS -1
@@ -276,7 +276,7 @@ test_thread_sort (gboolean sort)
   }
 
   /* It is important that we only have a maximum of 1 thread for this
-   * test since the results can not be guranteed to be sorted if > 1.
+   * test since the results can not be guaranteed to be sorted if > 1.
    *
    * Threads are scheduled by the operating system and are executed at
    * random. It cannot be assumed that threads are executed in the