Fix various typos (#272)

* Fix various typos

Found via `codespell -q 3 -S ./3rdparty -L ba,nin,numer,ro`

* Fix source typo in tests/crt_test.cpp

src/string.cpp

@@ -412,7 +412,7 @@ namespace bx
 				++ptr;
 				--stringLen;
 
-				// Search pattern lenght can't be longer than the string.
+				// Search pattern length can't be longer than the string.
 				if (findLen > stringLen)
 				{
 					return NULL;