RFR (XXS): JDK-8008944 correct typos

[Magnus Ihse Bursie]

Bug: https://bugs.openjdk.java.net/browse/JDK-8008944

Fix some typos in comments and messages, as pointed out by users.

Webrev: http://cr.openjdk.java.net/~ihse/JDK-8008944-fix-typos/webrev.01

/Magnus