[SECURITY-281] Demonstrating that GetNodeCommand and UpdateNodeCommand refuse to operate on Jenkins itself.

[FIX SECURITY-273] Require admin permission to check update sites

[FIX SECURITY-250] Restrict access to admin APIs

[SECURITY-232] Integrating Remoting build with blacklist

[FIX SECURITY-247] Prevent loading of MethodClosure from XML

[FIX SECURITY-241] Compare API tokens in constant time

[FIX SECURITY-238] Don't echo command name

[FIX SECURITY-245] Compare crumbs in constant time

Integrating remoting 2.53.2

[FIX SECURITY-234] Abort plugin/core update on checksum mismatch

[FIX SECURITY-233] Remove multipart form exception from crumb filter

[FIX SECURITY-225] Add RequirePOST annotations

[FIX SECURITY-95] Add CSP headers to files served by Jenkins