Reviewed-by: jnimeh, mullan, wetmore, ahgross, asmotrak

Summary: It is a re-merge of JDK-7030966.
Reviewed-by: wetmore

Reviewed-by: valeriep

Reviewed-by: weijun, wetmore, valeriep

Reviewed-by: alanb, xuelei

Summary: the signature of server key exanage message could be null
Reviewed-by: vinnie

6985179: To support Server Name Indication extension for JSSE client
Summary: Introduces the algorithm constraints to support signature and hash algorithm selection. Includes contributions from wetmore and weijung.
Reviewed-by: wetmore, weijun

Reviewed-by: darcy, weijun

Reviewed-by: wetmore

Reviewed-by: wetmore

Reviewed-by: alanb, mullan, wetmore

Reviewed-by: mullan, vinnie
Contributed-by: stephen.flores@oracle.com