More misc. typos

found via `codespell-q 3`
please review
diff --git a/png.h b/png.h
index cba3e88..04c36b5 100644
--- a/png.h
+++ b/png.h
@@ -1137,7 +1137,7 @@
  * corresponding composited pixel, and the color channels are unassociated
  * (not premultiplied).  The gamma encoded color channels must be scaled
  * according to the contribution and to do this it is necessary to undo
- * the encoding, scale the color values, perform the composition and reencode
+ * the encoding, scale the color values, perform the composition and re-encode
  * the values.  This is the 'PNG' mode.
  *
  * The alternative is to 'associate' the alpha with the color information by
@@ -3217,7 +3217,7 @@
  * option and 'onoff' is 0 (off) or non-0 (on).  The value returned is given
  * by the PNG_OPTION_ defines below.
  *
- * HARDWARE: normally hardware capabilites, such as the Intel SSE instructions,
+ * HARDWARE: normally hardware capabilities, such as the Intel SSE instructions,
  *           are detected at run time, however sometimes it may be impossible
  *           to do this in user mode, in which case it is necessary to discover
  *           the capabilities in an OS specific way.  Such capabilities are