I've patched TextBlockInstruction so it evaluates
faster. I have changed internal representation of its
data from String to char. This way, the process()
method will call PrintWriter.print(char) instead of
PrintWriter.print(String) -- the Writer will need not
extract the characters from the String, effectively
sparing one "new char" and one "System.arraycopy()"
per process() call. I expect this to improve
throughput for templates that contain many and/or
large text blocks. The change is completely backward
compatible, as the interface of TextBlockInstruction
has not changed, only a private field's type and the
setText() method internals have changed.