Bug 492230 - Replace buffer.append(a+b) calls

When using a `StringBuilder` or `StringBuffer` to create a string message,
using implicit string concatenation inside an `.append()` call will
create a nested StringBuilder for the purposes of creating the arguments,
which will subsequently be converted to a String and then passed to
the outer StringBuilder.

Skip the creation of the intermediate object and String by simply
replacing such calls with `buffer.append(a).append(b)`.

Where values are compile time String constants, leave as is so
that the javac compiler can perform compile-time String concatenation.
Ensure that NEWLINE isn't appended in such a way since it is not
a compile time constant `System.getProperty("line.separator")`

Change-Id: I4126aefb2272f06b08332e004d7ea76b6f02cdba
Signed-off-by: Alex Blewitt <alex.blewitt@gmail.com>
72 files changed