RFR: 8159752: Grant de-privileged module permissions by default with java.security.policy override option

[Sean Mullan]

Please review this change to the default Policy provider implementation 
to grant de-privileged module permissions by default even when the 
java.security.policy override option is specified or when the 
Policy.getInstance API is used:

http://cr.openjdk.java.net/~mullan/webrevs/8159752/webrev.00/

A new system-wide policy file located in 
${java.home}/lib/security/default.policy has been created. It contains 
grant statements containing the permissions that need to be granted to 
de-privileged modules. These grant statements were previously located in 
the ${java.home}/conf/security/java.policy file and have been relocated 
to the default.policy file.

The default.policy file is now always loaded by the default Policy 
provider implementation (sun/security/provider/PolicyFile). It is loaded 
if the java.security.policy '=' or '==' option is specified, and also if 
the application uses the Policy.getInstance methods and specifies the 
"JavaPolicy" type. If the default.policy file cannot be loaded, an 
InternalError is thrown, on the basis that the runtime cannot operate 
correctly unless these permissions are granted.

The rationale for making this change is that the runtime should be 
responsible for granting the permissions it needs to operate correctly. 
We should not expect users to have to determine or copy and paste these 
permissions into their own policy files.

Thanks,
Sean