Adds test for odd bit length RSA key size

Also tidy up ChangeLog following review.
diff --git a/ChangeLog b/ChangeLog
index 9bf0b15..1dba929 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -16,7 +16,7 @@
      in the trusted certificate list.
    * Fix bug in mbedtls_x509_crt_parse that caused trailing extra data in the 
      buffer after DER certificates to be included in the raw representation.
-   * Fix issue that caused a hang up when generating RSA keys of odd bitlength
+   * Fix issue that caused a hang when generating RSA keys of odd bitlength
 
 Changes
    * On ARM platforms, when compiling with -O0 with GCC, Clang or armcc5,