Keep track of braces {} in @code comments

This makes doclava more compatible with javadoc, though
it retains some differences around escaping for the moment.

This is related to a change in Javadoc behavior in JDK 5, most
likely http://bugs.java.com/bugdatabase/view_bug.do?bug_id=4965490

Bug: 25757239
Change-Id: I2b4ba4dbad520a1a3e00f394e1fac4b8d67b3fbf
1 file changed