Relative path to pdb

Fix tagged release builds. PDB artifacts

Switch to Stable 3.5

More fixes for symbol storage

Store symbol artifacts only for Stable builds

Only specify 5.11 so minor version will float to whatever is on AppVeyor

-fixes #3756

 * appveyor too slow

* enable TCPLinkTest
* enable FileManagerTest

* [WIP] deploy release and daily build pdbs to s3

* First pass at windows symbol generation for #2680

* Kill the conflicted compiler flag warning

* Tweaks to windows compiler flags for release builds, more qt-ish release symbols and ltcg

* Deploy tagged release symbols and CI builds to different S3 folders

* Support LTCG on iOS

* Just turn off ltcg for iOS if it is going to be such a pain

- Include appveyor YAML script in windows build other files

See also: https://github.com/appveyor/ci/issues/743

* appveyor install nsis from s3

* Pass YAML linting, pls work

* Simpler nsis download scheme