http-client-branch: merge with default

http-client-branch: (WebSocket) cleanup. Removed not needed classes. I'll bring some of them in later, when I need them.

http-client-branch: (WebSocket) API update

http-client-branch: remove some degenerate test cases from BufferingSubscriberTest

http-client-branch: more debugging, and hopefully a fix, for a FlowTest intermittent failure (ERROR AT END)

http-client-branch: minor doc formatting

http-client-branch: (WebSocket) builder change

http-client-branch: review comment asFileImpl sneaked into the API

http-client-branch: more precision for GET() in HttpRequest.Builder

http-client-branch: more precision for headers in HttpRequest.Builder

http-client-branch: minor doc formatting in HttpRequest

http-client-branch: moved noBody() to HttpRequest.BodyPublisher

http-client-branch: better diagnosis of expected exceptions

http-client-branch: minor doc tweaks in HttpRequest

http-client-branch: typo in HttpClient.java

http-client-branch: minor doc tweak in HttpClient.java

http-client-branch: adding time information to BufferingSubscriberTest.java

http-client-branch: merge

http-client-branch: (WebSocket) the builder is immutable now

http-client-branch: minor doc change

http-client-branch: (WebSocket) immutable builder copy; illegal headers;

http-client-branch: minor doc change

http-client-branch: minor doc change

http-client-branch: HttpClient uses ProxySelector.getDefault() by default

http-client-branch: merge

http-client-branch: Update copyright years in tests

http-client-branch: Update copyright years

http-client-branch: Add a test for CONTINUATION frame handling

http-client-branch: spec clarifications and minor fix to sendXXX methods

http-client-branch: Cleanup unneeded buffer instance variable from Http1Exchange