BUG-1119: optimize length and range checks in generated sources.

Constraints are generated only once (by double-checked locking) and stored as immutable static variable.
BigInteger and BigDecimal values 0, 1 and 10 are represented as Big*.ZERO, ONE or TEN.
BigInteger values are created via BigInteger.valueOf(long) call.

Change-Id: Idb54d841fe64fd5a32af38b30126a314d6bc7a0d
Signed-off-by: Martin Vitez <mvitez@cisco.com>
Merge "BUG-1119: optimize length and range checks in generated sources."