setup 2.886 release candidate - please test

[Jon Turney]

A new setup release candidate is available at:

   https://cygwin.com/setup/setup-2.886.x86.exe    (32 bit version)
   https://cygwin.com/setup/setup-2.886.x86_64.exe (64 bit version)

Since this contains many internal changes, I think this could use some 
wider testing before being deployed. Please test and report any problems 
here.

This is not the place for setup feature requests.

Changes compared to 2.885:
- Apply default problem solutions in unattended mode
- Make --include-source work correctly in unattended mode
- Allow parser to accept an empty depends: list (2.885 (only) will 
report syntax errors when parsing setup.ini containing these, when the 
corresponding change to calm is deployed)