add cacheable option to client_context

Manual upmerge from 1.0.x to master.

Add missing flag option

Change permissions to run on Jenkins.

add more known failure msgs.

Fix file mode

Add a script to run performance sweeps

Add sync variants of important tests, add sweeps across different channel counts

Remove blah repos from the visualization

Increase log verbosity for benchmark driver

Support >16kib frame sizes in core

Improvements to CoreCLR support

Fix fuzzing detected failure

List undocumented things in core, c++

update and add new generate_protos script in csharp examples

update nuget client to latest version on performance workers

Percent encoding routines

change hint paths for protobuf to use net45 dir in csproj files

destroy byte buffer reader after use

Add Node 6 to the list of recognized compilers in run_tests.py

PHP: use ssl hostname override as auth audience uri if present

Grpc caching test

Manual upmerge from v1.0.x

build.yaml changes to make certain grpc++ builds work