IS_BETA is fragile

[srl295]

    public static final boolean IS_BETA = false;

What that does is turn on code that allows both ICU plus the beta data to be accessed,

It seems brittle to hardcode this; someone "in the know" needs to remember to toggle it when appropriate.
Why not compute it by comparing the current UCD.Settings version with ICU's UCharacter.getUnicodeVersion()?

[eggrobin]

Made obsolete by #659.