RFR 6483657: MSCAPI provider does not create unique alias names

[Ivan Gerasimov]

Hello!

Could you please help review the fix for this long standing issue?
Windows-MY allows non-unique aliases, but our implementation of KeyStore 
does not take it into account.

To help to deal with such keystores with multiple same-named aliases it 
is proposed to internally remap the keystore entries to aliases that 
artificially made unique.

I was meaning to create a regression test, but found no easy way to test 
this behavior, as the keytool program doesn't allow creating same-named 
aliases.
All existing regression tests pass well however.

BUGURL: https://bugs.openjdk.java.net/browse/JDK-6483657
WEBREV: http://cr.openjdk.java.net/~igerasim/6483657/00/webrev/

With kind regards,
Ivan