Remove obsolete docs links.
Remove downloading of the old releases list, and bundle the file in the repo.
Also the message in update-tags was wrong: we need git to do anything there now, as update-tags gets emscripten-releases using git currently (which is ok as update-tags is run by users that installed with git; otherwise they installed without git and just update the entire emsdk normally).
Previously we were asserting and generating a stack track if a
download failed. However the assert is only relevant if the download
succeeds.
Also:
- Remove an unused function
- Remove extra braces from tuple destructuring
This change moves the python code for emsdk into a file ending in .py.
This script is then run via emsdk.bat on windows or emsdk (a shell
script) on non-windows.
This avoid the #!/bin/sh at the top of the python script and the "exec"
hack on the first line that re-runs it under python. Hopefully this
preserves the intent of #273 without jumping through so many hoops.
